# Fileset [kakenhi-1996-5-236.xlsx](https://mdr.nims.go.jp/filesets/e4e63718-b8a4-4869-8786-ac3d3e832520/download) ## Creator National Institute for Materials Science ## Rights ## Other metadata [FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274 Physics and Chemistry of Functionally Graded Materials Research Report (pp.5-236)](https://mdr.nims.go.jp/datasets/eb6c6db7-624e-4e30-9e9a-b13d35b3916a) ## Fulltext Sheet1 BookTitle_j BookTitle_e Volume/Issue Issueddate Page Title_j Title_e AuthorList_j AuthorList_e Abstract Language 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 5-14 放電プラズマシステムによる傾斜機能材料の合成 Fabrication of Functionally Graded Materials by Spark Plasma System 大森守、平井敏雄東北大学金属材料研究所 Mamoru Omori and Toshio HiraiInstitute for Materials Research, Tohoku University The functionally graded materials were first developed as the thermal shield materials, the refractory parts used in the high-speed air crafts. Therefore the fabrication technique has been developed centering the combination of metal and ceramics. The main methods developed so far include CVD, PVD, electrodeposition method, plasma spraying, and powder metallurgy, etc. Among these the plasma spraying method has progressed to the point where it can be actually used to fabricate the thermal shield materials, at least in the stage of their trial fabrication. However, in many cases the graded layer synthesized by this method are porous. The authors have tried to fabricate functionally graded materials by spark plasma system (SPS) which has recently attracted attention as new sintering process. This method is a kind of powder metallurgy which makes it possible to synthesize densely consolidated functionally graded material from various kinds of powder with different sintering temperatures in a short time. In this report, fabrication of ZrO2(3Y)/stainless steel, ZrO2(3Y)/Ni, polyimide/Al, polyimide/Cu functionally graded materials that are dense without pores is reported. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 15-22 傾斜機能材料の傾斜化プロセス「傾斜機能材料の知的機能発現のための粒子配列プロセス設計」－粒子制御配列のための単分散粒子の作製－ The Process of Grading Materials: Design Of Intelligent Particle Configuration Process for Functionally Graded Materials -Preparation of Monodisperse Particles for Their Controlled Arrangement- 渡辺龍三東北大学　工学部 R. WatanabeFaculty of Engineering, Tohoku University In the fabrication process of functionally graded material from powder, it should be possible, at least in theory, to control the graded composition on the level of single particles. If that is realized, the materials with graded compositions will be much more diverse and many more new functions can be incorporated in the design of new materials. In this study program, our aim is to establish a particle configuration process in which individual single particles will be positioned at the allotted three-dimensional sites. Unlike the conventional powder filling techniques that can handle powder as aggregates of particles, this new technique will handle each of the particles as a unit of compositional control, thus making a very minute design possible. During the 1996 fiscal year, the method of particle preparation used as the raw material was discussed and the particle configuration process according to that method was developed. Here, the fabrication of the Pb-Sn spherical monodisperse particles is reported primarily. At present, the method of selecting spherical particles of the uniform size, namely, the spherical monodispersion solder powder, has not yet been sufficiently established. The particles selected by such methods as atomization method cannot have the desired uniformity and grain size can be diverse. Also the yield is bad and there is much loss. Though it is possible to produce the spherical particles with less than 10% grain size distribution by plasma rotation electrode method (the PREP method) and sol-gel method, the range of the particle size is limited, and it is difficult to get the monodisperse particles of the desired grain size. Therefore, the authors devised the pulsated orifice injection method as a way of producing the monodisperse particle of the desired size. We report here the effect of pulse change on the particle formation, because it is known to be an important factor in the process. By examining the effect, we tried to find the optimum conditions of the monodisperse particle preparation. Shape and surface analysis of the produced particles were carried out. The report also includes uni-dimensional (plane) arrangement of the spherical monodisperse particles, its sintering and the equipment for the controlled arrangement of the particles. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 23-30 MA複合粉末のプラズマ溶射による傾斜機能熱電皮膜の作製 Fabrication of Functionally Graded Thermoelectric Coatings by Plasma Spraying of Mechanically-alloyed Composite Powders 福本昌宏豊橋技術科学大学生産システム工学系 M. FukumotoDepartment of Production Systems Engineering, Toyohashi University of Technology The thermoelectric power generation which directly converts heat into electricity has attracted attention as one of the effective ways of energy utilization. The usual fabrication methods of thermoelectric conversion materials (TEC) are successfully applied in the laminating or joining of several elements in order to effectively multiply the output, because a single element is limited in its generation power. In many configurations of TEC, thick coating may be advantageous in laminating or joining, and also for larger cross sections. Therefore, thermal spraying is worthy of consideration among several processing methods because the thick coatings of hard-forming materials can be easily made. Forming polycrystalline and amorphous structure by thermal spraying is also effective for the enhancement of performance of the thermoelectric elements. In this study, Fe-Si and Si-Ge, the supposedly promising thermoelectric materials, are used. Among the Fe-Si materials the FeSi2 composition (the beta phase) yields the best thermoelectric performance. However, since the beta phase is the line compound, minute composition control and long-time heat treatment are required in order to obtain this phase. Therefore the usual method of simultaneous spraying of a mixture of the constituent element powder and the subsequent heat treatment will not yield the complete beta phase. Another problem reported in the use of the meltdown FeSi2 powder as the raw material is the Si shortage following thermal spraying or heat treatment. Coping with this problem involves very difficult compositional control and so far the processed materials do not show satisfactory output characteristics. In this study, the mechanical alloying (MA) method is discussed, including the way it facilitates the compositional and structural control resulting in the minute and homogeneous mixing of the powder composition, followed by the plasma spray to produce the functionally graded thermoelectric material in the form of a thick film. By the introduction of the MA method, more convenient and minute adjustment of dope element addition should be possible. And it is also hoped that the processing of the FGM in various forms such as lamination or combination of thick films will also be done more easily by plasma spraying the powder mixture. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 31-36 ゾル－ゲル法による傾斜化プロセス：傾斜機能光半導体薄膜電極の作製と光電極特性の評価 Preparation and Photoelectrochemical Properties of Semi-conductor Thin Film Photoelectrodes with Graded Bandgaps using Sol-Gel Method 横尾俊信　幸塚広光京都大学化学研究所 T. Yoko and H. KozukaInstitute for Chemical Research, Kyoto University The semiconductor electrodes that perform photoelectrolysis to split water into hydrogen and oxygen by the photoelectromotive force generated by solar light irradiation are used in what is called the solar energy conversion cells. These cells are hoped to be the means by which energy can be produced cleanly for the next generation. It is the efficient performance of the optical semiconductor electrode that holds the key to the actual application of this energy conversion system. Ever since Honda and Fujishima found titania to be corrosion free in the electrolytic solution during the process of photoelectrolysis, it has been believed to be one of the promising candidates for the optical semiconductor electrode material. However, due to its large bandgap of about 3eV, it is not possible to utilize visible wavelength of the solar light, and the energy conversion efficiency, as a whole is as low as 4%. On the other hand, any narrow gap semiconductors studied so far are known to have poor photoelectrochemical stability. To solve these problems by raising titania electrode response of visible light, various methods have been tried such as doping titania with metal ions and have it be carried with the sensitizing pigments. In this study, we tried (1) optimization of the band gradient in the thin film electrode of porous titania and (2) formation of the graded band structure in the oxide semiconductor thin film by the sol-gel process to develop the functionally graded optical semiconductor electrodes with high energy conversion efficiency. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 37-42 加圧燃焼合成法による傾斜機能材料の合成プロセス Processing of FGM by SHS/Compaction 大柳満之　辻上哲也　小泉光恵龍谷大学理工学部 M. Ohyanagi,T. Tsujikami,M. KoizumiFaculty of Science and Technology ,Ryukoku University The product of SHS usually comes in the form of powder or porous material. However, dense and consolidated material can be synthesized using a combination technique of this SHS and an external pressure applied by HP (hot pressing), HIP (hot isostatic pressing), explosive consolidation technique, high velocity forging, and/or centrifugal force. Our research program aims to investigate the process of FGM fabrication by means of SHS compaction. This year we focus on the fabrication process of the FGM in which a graded dispersion of the non-equilibrium material (in terms of thermodynamics and pressure) is formed in the refractory non-oxide ceramics. The process uses the technique of SHS/compaction that simultaneously synthesizes and densifies the material. This method involves a combustion synthesis in the solid powder pressure-transmitting medium such as casting sand followed by the immediate instant compaction. We would like to make the process work consistently. SHS/compaction has nonequilibrium processes due to the steep ascension of the temperature during the reaction and the immediate cooling off. During such processes the nonequilibrated materials such as diamond are not exposed in heat for a prolonged period of time. Therefore, even when high pressure is not applied, diamond can be dispersed and fixed in the refractory non-oxide ceramics without transforming to equilibriated material, i.e. graphite. Diamond, a typical of non-thermal equilibrium material, is also a highly hard material with excellent temperature conductivity, semiconducting properties and optical characteristics. It is expected that diamond will be widely used as low-cost industrial material in the twenty-first century. Therefore, the development of new composite materials of diamond combined with ceramics or alloy is being keenly sought. We needed to introduce graded dispersion of diamond in the matrix reactant in order to fabricate diamond containing materials. In this study, we used the TiB2-Si composite as the matrix. We used two systems in which the diamond is dispersed homogeneously and with a gradient to investigate the extent to which diamond can be concentrated by the SHS method when it is not followed by compaction. Next, SHS was followed by compaction to form a densified material, and the residual stress in this functionally graded material was calculated using the finite element method. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 43-48 組成およびポア構造傾斜高温セラミックフィルターの作製 Fabrication of High Temperature Resistant Ceramic Filter With Graded Composition and Pore Structure 小平紘平　高橋順一北海道大学大学院工学研究科 K. Kodaira and J. TakahashiGraduate School of Engineering, Hokkaido University As the materials that can be used in the development of the high temperature filter, cordierite seems to be the best suited material at this moment. The new energy conversion system using cordierite is now in the process of development. A suggestion has been made to fabricate a cordierite/mullite composite material to improve the reliability and resistance of the homogeneous cordierite system. Mullite has good resistance against heat and creep, and its thermal expansion coefficient is moderate. However, if mullite is to be simply dispersed in the cordierite system, there will be no remarkable improvement in the strength. Therefore, in this study, we aim to form a layer of compositionally graded material between layers consist purely of cordierite and mullite, in which porosity is also graded, using the spray method. Among various ways to form a compositional gradient, the chosen method was to spray on the surface of the cordierite layer, the graded layer, and then finish with a mullite layer inside. In this present research, the possibility of preparing a pure mullite layer separately as a base material and forming the graded layer on top of it was discussed. We applied spraying method to the fabrication of compositional gradient. We also decided to adopt the method of using two separate nozzles to spray the components, cordierite and mullite, with graded proportions and called it the double spraying method. We hope to form a packed bed with desired compositional gradient by first grasping spraying condition of the droplets onto the surface and then setting the nozzles accordingly. The graded proportion of each component will be formed by continuously changing the spray pressure. This year we assembled spraying equipment with the nozzles that produce the simplest spray patterns. Next we discussed the method of preparing the suspension and spray pressure optimum for the fabrication of the graded material. We then examined the resulted compositional gradient to find the problems and room for improvements to be handled next year. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 49-54 有機物前駆体法による非晶質傾斜セラミックスの作製 Synthesis of Amorphous Ceramics from Organic Precursor 佐々木眞室蘭工業大学　工学部 Makoto SasakiFaculty of Engineering, Muroran Institute of Technology C/C composites are thought to be usable as ultrahigh-temperature resistant material in aviation and space as well as for gas turbines once it is made oxidation resistant. However, not much research has been carried out about the materials resistant to oxidizing atmosphere that contains sulfur. To add oxidation-resistance to the C/C composite, the vapor deposition method has been tried to form graded coatings to fabricate the SiC/C and SiC/TiC graded materials. However, cracks can accidentally occur on the surface material of SiC/C, causing oxidation of the inside materials such as carbon, TiC and the base C/C materials. We have set as our goal to solve this problem by fabricating functionally graded materials with amorphous ceramics, consisting of Si-N or Mo-Si as the outermost material and Si-C-N or Si-B-C-N as the inside materials. In our program we use polymer precursors to form these graded amorphous ceramics and study their crystallization process with a view to clarifying the coating conditions for better oxidation resistance. The crystallization behavior of amorphous ceramics has been reported by Riedel et al. Also, Amano et al. has reported structural changes of the Si-N-C amorphous ceramics in high temperature. As for ceramics with boron, Allcock et al. have reported synthesis of the borazine (B-N-C-H)-based ceramics, and Baldus et al. have reported the synthesis of another ceramics after adding boron to silazane, using this polyborosilazane (Si-N-C-B-H) as the base material. However, many questions remain as to the synthesizing methods and properties of these new ceramics. We therefore tried synthesis of polymers consisting of Si-C-N-H and Si-B-C-N-H, and investigated the conditions to form graded amorphous, and crystallization of amorphous ceramics. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 55-60 ナノスケールで変化した傾斜構造の物理的・力学的挙動の原子レベルシミュレーション Atomistic Simulation for Physical and Mechanical Properties of Nano-scale Graded Structure 相原智康　川添良幸東北大学金属材料研究所 Tomoyasu AIHARA and Yoshiyuki KAWAZOEInstitute for Materials Research, Tohoku University The application of FGM's concept for the interface control at the atomic level will very likely enhance the performance of the material. To make such fine control possible, the nano meter level technology must be established to evaluate the physical and mechanical properties locally, and to design the optimized graded structure on the atomic level. In order to be able to handle the materials on nano-level order, deepen our understanding on the mechanism of the macroscopic functional expression and to establish basic guidelines for designing new materials, we have carried out several different simulations using the molecular dynamics (MD) method in the atomic level. So far our calculation regarding formation and mechanical behavior of the amorphous alloys, dynamics of grain boundary of intermetallic compound, and spinodal decomposition in random structure etc. supports the experimental observations well. We have accumulated new findings that were not available by the conventional experimental methods in terms of their physics. Now we are working on the simulation of functionally graded materials by calculation of thermal stability using the continuum modeling. In the present research, we performed molecular dynamics calculation of the interface between heterogenous phases in Ni-based heat-resisting superalloy, as the atomic level simulation of the nano-scale graded structure. The object of the calculation is coherent interface between Ni3Al ((gamma)' phase) and Ni ((gamma) phase) of the L12 type intermetallic compound. In Ni-based superalloys including the Ni-Al2 system, the (gamma)/(gamma)' interface generally matches in the (100) plane. It is known that the misfit of (gamma)/(gamma)' lattice constant greatly affects the strength of Ni-based superalloy under high temperature strength. However, many questions remain as to the atomic level structure due to the lack of enough experimental data, which directly focus on the interface microstructure. In this fiscal year, we aimed to establish the technique which theoretically clarifies physical and mechanical properties on the microscopic level and to evaluate the characteristics of nano-scale gradient in the(gamma)'/(gamma)interface structure, and carried out molecular dynamics simulation of the Ni/Ni3Al interface. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 61-72 レーザーCVD法による選択的光化学反応を用いた低温プロセスによる傾斜機能材料 FGM Processing Under Low Temperature Using Selective Photochemical Reactions By the Laser CVD Method 伊藤攻　渡辺明　藤塚守東北大学反応化学研究所 Osamu Ito, Akira Watanabe, Mamoru FujitsukaInstitute for Chemical Reaction Science, Tohoku University As a fabrication method of functionally graded material (FGM) with silicon atoms, the CVD method using thermal decomposition reaction of reactive gas on the substrate has been the primary method. However, handling highly concentrated silane gas has safety risks. Also, the substrate must be heated up to high temperature to form a graded thin film by the CVD method. In this study, we aimed to establish a method to form a gradient using photochemical reaction of organic compounds by laser beam at a low temperature. Silane gas, the primary raw material for the silicon thin film formation, can be considered the "zero order", or none-dimensional, material. Low-molecular organic silicon compounds can also be considered as none-dimensional compared to the three-dimensional silicon skeleton, but it is more stable than the silicon gas because of their intermolecular heteroatoms such as carbon atoms. Organopolysilane is an example of the unidimensional silicon skeleton with the stabilized structure. The silicon ring compounds can be positioned in between the none- and unidimensional silicon. These molecules can be used to form a thin film by the vapor deposition method. As two-dimensional silicon, the polysilane with the net-shaped framework of silicon skeleton has been synthesized. As a silicon compound with the skeleton of higher order dimension, we have recently synthesized the organic silicon nano-clusters. There is less risk in handling these compounds with higher dimensions than silane gas, and we think they could be used as precursors of silicon thin films. This paper focuses mainly on the processing of low-molecular silicon thin films and graded materials using the laser CVD mentioned in the title, with a view to developing a new FGM fabrication technique separate from the conventional CVD method. We also report here the fabrication method using other low-molecular silicon compounds. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 73-80 アルミニウム拡散浸透処理によるTi/Al3Ti傾斜機能材料の作製 Fabrication of Ti/Al3Ti Functionally Graded Material Using Aluminum Diffusion Infiltration 友田陽、辻本得蔵、太田弘道、鈴木徹也茨城大学工学部 Y.Tomota, T.Tsujimoto, H.Ota, T.SuzukiFaculty of Engineering, Ibaraki University Although titanium alloys such as Ti-6Al-4V are known as heat-resisting material, the upper limit of temperature in use is about 600deg.C. This limitation is not due to the material's mechanical properties but is caused by the lack of its oxidation resistance in high temperature. It seems that the improvement of the oxidation resistance can widen the application range of titanium alloys. One might consider coating the surface of the alloys with the oxidation-resistant material, but there is always a problem regarding the adhesive to bond the coating to the base metal. It is especially necessary to avoid the peeling by the thermal stress caused by the difference in thermal expansion coefficients. The coating materials should have excellent heat and oxidation resistance, but even more important is relaxation of thermal stress. In this sense the intermetallic compounds with properties that are closer to metals than ceramics is advantageous. It is desirable also to avoid stress concentration at the interface by forming a gradient of materials. This research program therefore tried the aluminum diffusion infiltration into titanium to form the Ti-Al intermetallic compound on the surface with an aim to fabricate very oxidation resistant Al3Ti. It is known that aluminum-rich compounds form a tight oxide film of Al2O3 on the surface and this makes the material highly resistant to oxidation. Although there have been some other reports on aluminum diffusion infiltration with the intention to improve oxidation resistance of titanium or TiAl, the cyclic thermal oxidation test of high and low temperatures showed the development of columnar crystals of TiO2 where AlTi did not exist at the external layer. These columnar crystals permit easy diffusion of oxygen, resulting in deteriorated oxidation resistance. The concentration of thermal stress at the interface can be one of the causes of this. Thus we tried to make the interface as irregular as possible in shape so that thermal stress could be relaxed under the cyclic thermal test. Chromium was added on the surface with the aim to further improve oxidation resistance and mechanical properties of the external Al3Ti layer. The material was treated with chromium and aluminum under different conditions (which we called the complex diffusion filtration). Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 81-86 電気泳動法による磁性フェライト材料の傾斜機能化プロセスの開発 Processing of Ferrite Functionally Graded Material by Electrophoresis 宇都野太東京大学　生産技術研究所 Futoshi UTSUNOInstitute of Industrial Science, University of Tokyo The concept of functionally graded materials (FGM) is to optimize thermal expansion coefficients and thermal conductivity of the composite materials according to the needs in particular environment. This is achieved by giving appropriate gradient between the components of the materials, e.g. a ceramic coating and metal, or between different ceramics to solve the problems in bonding. Application of this concept to many other materials is being discussed, and several research and development programs of the processing technique of FGM are being undertaken. In our program, we aim to establish a liquid-phase processing method of ceramics/ceramics FGM by electrophoresis. The electrophoresis is the method to produce electric field on the substrate plate, which is placed in the suspension fluid of fine particles of materials such as ceramics. The particles travel toward the substrate to be piled and stacked on it. This technique is cheaper than vapor deposition methods such as CVD and PVD, plasma spraying method, powder molding and SHS method, and fiber alignment technique; and it is advantageous in forming a film uniformly on a comparatively large area. There has been a number of reports on the electrophoresis technique, but only a few reports have been published on the use of suspension fluid that is a mixture of two or more kinds of particles. So far we have only had trial and error experimental procedures to find a way to control the film formation. In our study, we discussed the application of FGM fabrication process using the suspension fluid containing 2 kinds of ceramic particles by means of electrophoresis. We aimed to form a graded thick film, which consists of zinc ferrite (ZnFe2O4) and Fe2O3, in which a gradient is formed by controlling the value of x in ZnxFe2-xO4. In addition, controlling method of various other factors such as the type of suspension solvent and its pH was discussed, because those factors affect the amount of the particles that can be deposited on the substrate. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 87-92 ソフト溶液プロセスによるセラミック/金属系傾斜機能材料のin situ作製 In situ Fabrication of Ceramics/Metal Functionally Graded Materials by Soft Solution Processing 吉村昌弘　八島正和東京工業大学応用セラミックス研究所 Masahiro Yoshimura, Masatomo YashimaMaterials and Structures Laboratory, Tokyo Institute of Technology We have come to realize that constituents of all living organisms (including ourselves) and ecosystems are basically aqueous. Therefore we believe that, if we can fabricate new materials through the fabrication process using the aqueous solutions, there will not be much damage to the environment. Based on this concept, we suggest the fabrication process be developed to produce highly functional ceramics and other new materials without wasting energy in the form of extreme high temperature and so on. This process can produce the material directly from (or in-situ) the aqueous solution. We have proposed to call this process "soft solution process". The advantages of the soft solution process, in which highly active aqueous solutions have hydrothermal, electrochemical or other forms of reactions with the substrates, are as follows: (A) it does not have to be followed by the heat treatment because highly functional ceramic films such as complex oxides and carbon films are formed directly (or "in situ") on the substrates; (B) since homogeneous liquid is used in electrochemical reaction, ceramics can form as a "cover" of the substrate; therefore the shape of the film can be determined by that of the substrate; (C) the advantage mentioned above means that the aqueous solution can be used to form compounds inside the materials of complicated shape or even porous materials. The purpose of our research program was to produce ceramic/metal FGM (metal part being laminated films or layers) with desired shape and size "in situ", or directly, without wasting energy in the form of high temperature heat etc. We aimed to do this by applying the knowledge we gained from our long-term research projects on hydrothermal and electrochemical reactions. Based on such knowledge, the metallic substrate was reacted with the aqueous solution (or its components). By altering the composition of the component (solutes) during the reaction, the film's composition and structure can be graded. Though many reports exist regarding the formation of ceramic films from the aqueous solution, our report is unique in proposing the crystalline composite ceramic films directly in the solution by its reaction with the substrate. This finding has enjoyed international recognition. During this fiscal year, we aim to fabricate the metal/ceramics FGM by synthesizing the scheelite type AWO4, AMoO4 (A=Ca,Sr,Ba) or its solid solution on the tungsten metal substrate. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 93-98 無機－有機傾斜複合体の合成と構造解析 Preparation of Porous Inorganic-Organic Functionally Graded Complexes and Structure Analysis 熊田伸弘　木野村陽一山梨大学　工学部 N. Kumada and N. KinomuraFaculty of Engineering, Yamanashi University Though the primary field of application of the inorganic-organic graded compounds has been biomaterials, we believe that new composite materials with "firmness" of inorganic compounds and "softness" of organic compounds can be used for other purposes. For example, it seems possible to synthesize the new porous compounds with different pore size by forming such inorganic-organic gradient on the two-dimensional inorganic layer. Right selection of the organic molecules with different types and sizes should make free control of pore diameters possible. In this study, we aimed to fabricate the inorganic-organic functionally graded complexes using zirconium phosphate as inorganic layer and forming an organic phosphate-inorganic phosphate gradient on the layer surface. In addition, the organic compound that does not easily bond to the layer, such as aniline, was intercalated between the layers when the complex was prepared. Aniline was to be removed by subsequent heat treatment to form a new porous compound. Fig.1 shows the schematic design of the inorganic-organic functionally graded complex and the porous material we tried to fabricate. In this study, we used phosphonic acid as organic phosphorous compound. As the starting materials, zirconium oxychloride, phosphoric acid, phenylphosphonic acid, hexylamine and aniline were chosen and reacted in hydrothermal reaction to synthesize the inorganic-organic functionally graded complexes. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 99-104 分子軌道法による金属－セラミックス系酸素イオン濃度傾斜材料の電子構造の計算 Calculation of Electronic Structure in Metal/Ceramic FGM with Graded Oxygen Ion Concentration by Molecular Orbital Method 森永正彦　湯川宏名古屋大学　工学部 Masahiko Morinaga and Hiroshi YukawaNagoya UniversityFaculty of Engineering In an attempt to combine different materials and produce new functions by forming a gradient between them, we need to come as close as possible to the electron-level approach in searching for the fabrication method of such a new graded material. Authors have examined the electronic state of the system in which hcp titanium is superimposed on fcc nickel. For example, the change of the electronic state in the composite material of these metals was calculated using three cluster models shown in upper diagram of Figure 1. The Figure also shows the state density of each of the two metals, before (a) and after (b) combining them. By forming a composite material from these two metals, electrons transfer from Ti to Ni, and the resulted Fermi level is in between the Fermi levels of Ti and Ni. However, such change is fairly predictable, and in the combination of similar electronic structures like those of nickel and titanium, there seems to be few new functions that result from combining or forming a gradient of the two. In other words, looking at new functional expression from the standpoint of electron theory, it seems more promising to form a gradient between the materials with very different electronic structures rather than between two metals. Especially, metal/ceramics functionally graded materials should have greater potential for interesting new functions, since electronic state continuously changes from metallic one to another kind with the energy band gap. The purpose of this study is to calculate the electronic structure of metal/ceramics composite materials (Fe/FeO and Zr/ZrO2) with graded oxygen ion concentration, and to obtain fundamental knowledge of the physical and chemical properties of metal/ceramics functionally graded materials in the electron level. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 105-110 傾斜化プロセスの高分解能分析電顕内その場観察 In-situ and Real Time Observation of Gradient Formation Process Using High Resolution Electron Microscope 坂公恭名古屋大学工学研究科 HIROYASU SAKANagoya UniversityGraduate School of Engineering The purpose of this study was to observe the in-situ gradient formation process using electron microscope at the real time and at the atomic level high resolution. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 111-116 傾斜高分子膜の作製および気体浸透メカニズム　－非対称シロキサン-イミドブロック共重合体薄膜の作製および気体浸透 Preparation and Gas Permeation Mechanism of the Graded Polymeric Membranes I -Preparation and Gas Permeability of Asymmetric Siloxane-imide Block copolymer Membranes- 辻田義治名古屋工業大学工学部 Yoshiharu TSUJITADepartment of Materials Science and Engineering, Nagoya Institute of Technology Polyimide films with characteristics of heat-stability, solvent resistance, and excellent mechanical properties are especially used to electronic devices which require heat-stability, low dielectric constant, thin film formability and so on. Polyimides have possibility of various kinds of structure composed of various dianhydride and diamine moieties, namely various primary structures, giving rise to various possible functionality like gas separation and permeation. In the field of membrane technology, highly permeable membrane is expected to be developed. Polyimides are possible to be utilized as relatively gas separative and permeable membrane with high temperature heat stability. Furthermore, one would expect advanced membrane performance of polyimides designed by various molecular structures. In the present paper, the siloxaneimide block copolymer was used to prepare the asymmetric membrane by cpoling and succeeding freeze-drying method in order to develop highly permeable membrane, and the morphology, dynamic mechanical property, permeability and permselectivity of the membrane are examined. This membrane is one of the graded polymeric membranes because of the asymmetric morphology along the thickness direction. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 117-124 繊維への傾斜コーティングによる多機能複合材料界面の創製と強靭化 Invention and Toughening of Interfaces in Multifunctional Composite Materials by Coating Fiber with FGM 落合庄治郎、北條正樹、井上忠信京都大学工学部附属メゾ材料研究センター Shojiro Ochiai, Masaki Hojo, Tadanobu InoueMesoscopic Materials Research Center, Kyoto University Composite materials are fabricated by combining different materials with the intention to create new properties that are not expressed in starting materials. Such new properties result from positive effects of combining different materials as interactions of different characteristics peculiar to each starting material, and/or the effect of interfaces. Interfaces mean not only division and discontinuity in between the different materials but also scattering, reflection, absorption and inducing interactions of the components. Based on this concept, glass and carbon fiber reinforced plastic, FRM, etc. are produced as structural materials, some of which have been already put to use. In the process of developing these materials, the interface control, such as surface treatment of the fiber to react with the coupling agent and coating of fiber, is important. However, the characteristics that can withstand severer conditions are required in the case of composite materials today. Single coating to prevent interfacial reactions, for example, may have been sufficient to make the material workable in the past, but now we need new technologies based on new concept to realize new and high-performance composite materials. We must employ new ideas and techniques that simultaneously satisfy the requirements for advanced functions, such as preventing degradation that results from reactions, optimizing the adhesive strength, and stopping crack development. We intended to realize these purposes by applying the concept of functional gradient to the coating layer itself. During this fiscal year we aimed to collect just basic knowledge by: (1) trying to formulate a function for functional optimization from the standpoint of thermal stress control, and (2) grasping the effect of a graded coating layer on modes I and II crack propagation. In order to achieve the other goal, namely, to apply the graded coating for the performance enhancement of functional composite materials, we are preparing for another research program involving superconductive Nb-Ti composite wire material. Multiple necking is formed in the Nb-Ti filament under the stress load to lower the critical current. In order to improve the critical current, the formation of multiple necking must be suppressed. Therefore we try to (3) fabricate a graded coating on copper by dispersing the oxide particles in the filament so that the necking formation, and not heat conduction, is suppressed. This experiment is underway now, but we concentrate here on (1) and (2) above. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 125-132 非平衡プラズマプロセスを用いた有機傾斜機能性薄膜材料の開発 Development of Organic Functionally Graded Thin Film Using Nonequilibrium Plasma Process 内本喜晴、小久見善八＊京都大学大学院エネルギー科学研究科、＊京都大学大学院工学研究科 Y. Uchimoto and Y. OgumiKyoto UniversityGraduate School of Energy ScienceDepartment of Fundamental Energy Science*Kyoto University The fuel cell is the electrochemical system that converts chemical energy of fuel, reacted with oxygen, directly into electric energy. The fuel cells have better energy conversion efficiency than heat engines in thermal power generators and other types of plants, and much cleaner because only a very little amount of NOx and SOx is produced. Therefore it is hoped that the use of the fuel cells will help solve the problems related to environmental destruction and thermal pollution on a global scale, and they are expected to work as power generating system in the future generation. Research and development of solid polymer electrolyte type fuel cell (PEFC) with the fluorine-based ion exchange membrane as the electrolyte is actively progressing especially as the power source of electric automobile, since power density can be high in this system. For further enhancement of performance, it is necessary to reduce overvoltage at the electrode, especially oxygen overvoltage at the cathode where activated overvoltage is high. For that purpose, the reaction zone must be expanded by making it three-dimension. Also, the exchange current density must be increased by raising oxygen concentration in the electrode/electrolyte interface. Since solubility of the oxygen is high in the hydrophobic fluorine polymers, it is possible to increase the effective electrode surface area by coating the catalyst electrode with ultra thin film of fluorine polymers. Also by forming the ion conduction pass by covering the film with ion conductive thin layer, the area of interface where the electrode process can occur increases eve n more. In order to bond the ultra thin hydrophobic film made of fluorine polymers and the hydrophilic ionic conductivity thin layer with tight adhesion, the concept of FGM must be applied. Using this method, it is possible to fabricate very active gas electrode, but conventional methods would not allow us to make such thin film. In this study, it was aimed to establish a manufacturing method of molecular-designed functionally graded organic thin film using nonequilibrium plasma, and use it to modify the PEFC electrode/electrolyte interface. Figure 1 shows the gas diffusion electrode of PEFC we tried to fabricate this year. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 133-138 ゴム系傾斜機能複合材料の作製とその物性 Preparation and Properties of Functionally Graded Rubber Materials 掬谷信三　村上昌三　池田裕子＊京都大学化学研究所、京都工芸繊維大学工芸学部 S. Kohjiya, S.Murakami and Y. IkedaKyoto UniversityInstitute for Chemical Research*Kyoto Institute of Technology Faculty of Engineering and Design The polymers can be called, in a certain sense, a kind of functionally graded material, because of their polydispersity molecular weight distribution. The component distribution of copolymers is not usually uniform either, which is peculiar with giant molecules. Therefore, designing functionally graded materials may seem easy with polymers using such methods as blending, copolymerization, interpenetration network (IPN) method, etc. However, accurate experimental characterization of graded physical properties is often very difficult with polymers, so in actuality realization of graded polymers is a tough research project. We decided to start such research project on functionally graded material prepared from polymers, focusing on the material, which showed rubber elasticity at the room temperature. The elastomer is the material with the following dynamic properties: about 1 to 10MPa Young modulus, over 5MPa tensile strength and over 100% elongation at the room temperature. In the field of industry, the composite materials consisting of three-dimensional network structure and filler is used as elastomer in many cases. In the processing, mastication and mixing are followed by cross-linking reactions to form the network structure, and it was made a point to have the cross-linking reactions uniformly in the whole system. However, we came up with the idea of reversing what was considered disadvantage to advantage: we aimed to form a graded material by forming a gradient in the cross-link density in elastomeric material. Then the basic mechanical properties and structure were evaluated systematically, and the way to use the filler with a graded density was discussed to develop new graded composite rubber material. Then, by clarifying of the relationship between the structure and physical property, the development to the functional material was attempted. Our ultimate goal is to fabricate the material that contributes to the development of sound and vibration proof rubber materials in the wide frequency range. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 139-146 傾斜組成材料を用いたケミカルバイメタルの開発 Development of Chemical Bimetal Using Graded Composition Material 山田武、木村良晴、大野原基京都工芸繊維大学・繊維学部 Takeshi Yamada, Yoshiharu Kimura and Motoki OnoKyoto Institute of Technology Faculty of Textile Science Bimetal and hygrometers, etc. are used as the sensors using expansion coefficients. We thought many new sensors could be developed if expansion and contraction caused by chemical reactions were amplified by the bimetal effect, since such reactions are common among many materials. When two kinds of metallic thin plates with differed thermal expansion coefficients are welded to form a sheet, the bimetal effect can cause the sheet to bend to a desired degree depending on the kind of metal used. We also decided to try the polymer gel to develop the chemical bimetal that could be used repeatedly. It is known that cross-linked polymer gel autonomously respond to the environmental changes and adjust its shape accordingly. By using the polymer gel which has chelate compounds as functional groups as the component of the reaction layers, it is possible to synthesize chemical bimetal that bends responding not only to alkali and acid but also to metal ions. However, polymer gel films with water can not bond to polymer membranes. Even if the film and the membrane can be bonded, when one of them contracts, considerable stress is applied at the interface. The graded water molecule concentration (higher concentration at the outer layer and lower at the inner layer) can eliminate stress concentration. Therefore, the material can be expected to have good response and durability. In this study, we used styrene-divinylbenzene as the basic skeleton of the polymer gel in order to make the structure three-dimensional in the aqueous solution. Ethylenediamine group was used as the functional group so that the synthesized polymer gel responds to acidic and alkaline environment as well as to metal ions. As a constructive method of the chemical bimetal, bulk polymerization was carried out in the solution of styrene, chloromethylstyrene, and divinylbenzene to form a film. Then the ethylenediamine solution was reacted with chloromethylstyrene on one side. This was done with intention to form a reactive film with graded concentration of the ethylenediamine, which is high on the surface but gradually lowers toward the inside. Thus the development of the functionally graded chemical bimetal was realized. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 147-156 ナノ構造制御による傾斜機能材料の製造と機能評価 Fabrication and function evaluation of functionally graded materials by nanostructure control 新原晧一　関野徹　左容昊大阪大学産業科学研究所 Koichi Niihara, Tohru Sekino, Y. H. ChoaOsaka UniversityInstitute of Scientific and Industrial Research Corresponding to the current expansion of application field of ceramics, the composition of ceramic materials has been attempted. We have developed nano composition technologies and studied the property improvement of the ceramic-based composite materials by nanostructure control. As a result, we succeeded in developing Al2O3/SiC, Si3N4/SiC, MgO/SiC ceramic-based nanocomposites by simple sintering processes and have found that the mechanical properties of those materials in room temperature and high temperature can be remarkably improved. By introducing various nano-sized dispersed phases into ceramics, each mechanical property also improves by 2 to 4 times. The TEM observation shows that, in each composite material, minute dispersed particles of 100nm or less exhibits a typical nano composite structure which is dispersed inside the crystal grain and grain boundaries of the matrix such as Al2O3 and Si3N4. Recently, based on the above result, we have been developing the ceramic/metal system nanocomposites of which second dispersion phase has metal grains with functions different from those of the nanometer-sized ceramics. In this system, the following can be expected; mechanical property improvement of composite materials by the high strength and toughness mechanism , toughening and material fabrication which furnishes functions of the nano-sized metal. In addition, by controlling the microstructure of materials with different functions, the fabrication of "functionally graded materials" in which properties of from ceramics to metal are continuously changed can be expected as well. Aiming at developing nano ceramic/metal functionally graded materials as a new material, we have carried out a series of research on the correlation between examination of the processing, improvement of mechanical properties, quantification of the microstructure and its mechanical properties and proved that the ceramic mechanical properties can be drastically improved even by the dispersion of nano-sized metal. This paper shows the high-resoluble TEM observation result of the interface structure and the characterization of the microstructures of the mutual nano compound type ZrO2/Mo-based nanocomposites as well as the grain boundary and transgranular type Al2O3/metal (W, Ni, Ti, etc.) nanocomposites produced by various methods, and it reports the relation with the mechanical properties of these composite material. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 157-162 熱緩和分散法（RAD法）による超微粒子分散傾斜材料の創製 Fabrication of Superfine Particle Dispersed Graded Material by Relaxative Auto-Dispersion Process (RAD) 出来成人　水畑穣神戸大学工学部 Shigehito Deki and Minoru MizuhataKobe UniversityFaculty of EngineeringDepartment of Chemical Science & Engineering We have found and reported on a new technique (RAD method-Relaxative Auto-Dispersion Process) in which ultrafine metallic particles of monodispersion-the particle size of a few scores of nanometers-can be dispersed in a polymeric medium in a solid phase condition. In this method, a metal layer is deposited over a vapor deposition polymer layer and by heating up to the temperature below the pour-point of polymers (in the case of nylon 11, around 70deg.C), the metal is uniformly converted into dispersion ultrafine particles. This dispersion method is a preparative procedure of a new ultrafine metallic particle dispersion composite. Recently, it has been found out that the dispersion of metal in the solid phase condition is possible by using these techniques which enable to make the matrix amorphous metal or amorphous semiconductor. We have carried out research on various thermal relaxation mechanisms of the amorphous metal material and succeeded in dispersing ultrafine Au and Cu particles in metallic glass of the Fe-Ni-based metal base. As the change in the crystallization mechanism in the lamination metal system is identified as a remarkable transition phenomenon, this system seems to be an optimum one for the consideration of the effect of the amorphous material metastability upon the dispersion of the lamination metal. In this study, as an example, a metal/semiconductor laminated body was produced, on which gold and amorphous germanium are deposited as metallic thin films and the matrix metal respectively, and thermal relaxation dispersion was attempted. In addition, the composition distribution in the metallic depth direction after the dispersion was measured by XPS, and its unique crystallization process was examined. The profile of the metallic dispersion by this technique changes with the dispersion temperature and time, and it was confirmed to be a complicated one which cannot be explained as a simple system such as the solid state diffusion generally observed until now. Our aim is to explore the possibility of manufacturing a composite material with functionally graded ultrafine particles using this dispersion technique of various metals and their metal compounds, and to clarify this dispersion mechanism, so that we can develop the manufacturing method of a completely new graded material which utilizes the crystallization process of the amorphous material. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 163-170 非対称性高分子膜の構造形成時におけるミクロ相分離機構の解明 Analysis of Micro-Phase Permeation-Separation Mechanism in Structural Formation of Asymmetric Polymeric Membranes 松山秀人、北村吉朗岡山大学 環境理工学部 環境物質工学科 Yoshiro KITAMURA and Hideto MATSUYAMAOkayama UniversityFaculty of Environmental Science and TechnologyDepartment of EnvironmentalChemistry and Materials Considering polymer membranes, it is necessary to reduce the thickness to an utmost degree since the permeability rate lowers if the membrane is thick. However, as the membrane thickness decreases, the mechanical strength lowers and pinholes are more easily formed. Such a dilemma can be solved by fabrication of a graded material (asymmetric membranes). That is to say, an asymmetric polymer membrane is a graded structure body which has an uniform skin layer on one side and a porous sponge layer on the other, therefore it has an advantage of the combination of high selectivity, high permeability and high intensity as the skin layer maintains permeability separation selectivity and the supportive sponge layer has high permeability. The asymmetric polymer membrane is generally produced by NIP method (Nonsolvent Induced Phase Separation) which induces phase separation by raising the nonsolvent concentration and also by TIPS method (Thermally Induced Phase Separation) which cools down the uniform solution and quench it to the two-phase region. Though the manufacture of an asymmetric membrane has conventionally depended on trial-and-error approach technologies, in the present situation, such trial-and-error methods cannot contribute to developing new materials, and thus the quantitative analysis on the structure formation has been expected earnestly. In this study, the manufacture of a new graded structure (asymmetric structure) membrane using NIPS and TIPS methods is aimed at. The principal objective of the research is to quantitatively analyze the phase separation process during the structure formation and to effectively design and control the structure. The summary of the research program is shown in Figure 1. This fiscal year, with regard to NIPS method, the asymmetric pore structure formation in the cellulose acetate/acetone/nonsolvent three-component system was examined. To begin with, the phase equilibrium relation of the polymer solution was clarified. Then, the simulation of the solvent volatilization process by the dry process was attempted, and the change in polymer concentration distribution in a film was required. Based on these results, the quantitative discussion was held on the relation between the obtained membrane structure and the membrane production condition. Additionally, the clarification of the coarsening of the phase (drop) as well as the phase separation mechanism in the metastable region was also examined. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 171-176 多核錯体の逐次吸着を利用する傾斜機能材料の作成 Preparation of Functionally Graded Materials by Means of Stepwise Adsorption of Multinuclear Complexes 一ノ瀬泉　安藤玲子九州大学工学部 I. Ichinose ans R. AndoFaculty of Engineering, Kyushu University In order to grade the chemical functions of solid material, it is necessary to convert functionally graded material of the conventional phase level to material with finer composition distribution. In this study, by using the stepwise adsorption of polynuclear complex to the solid surface, the manufacture of various functionally graded thin films with molecular sequence structures was examined. Especially, this study focused on the grading of the chemical function and aimed at the development of functionally graded thin films which have characteristics such as selective material transmission, reaction separation, excellent catalytic activity as well as molecular recognition, etc. For this reason, it is necessary to bear in mind the precise combination of various functional organic compounds such as electrically conductive polymers, pigment, protein and so forth. In other words, the establishment of manufacture process of various thin films by a mild wet method was set to be the primary goal. In this study, two different thin film preparation techniques based on chemisorption or electrostatic interaction were developed in order to achieve the above purpose. We have observed some phenomena in which polyelectrolytes with electric charges opposite to each other are alternately adsorbed very regularly in the aqueous solution. One of these techniques has been confirmed to be widely applicable to molecular aggregates including water-soluble molecules such as protein and pigment molecules or bilayer membranes and etc. In this study, first of all, the application of such an alternate adsorption process to the heteropoly acid of diameter of about 1 nanometer was examined. In the meantime, a surface sol-gel method was newly found in this study as the second technique for the laminating of polynuclear complex. In this technique, a series of operations, consisting of the chemisorption of metalalkoxide to solid surface with the hydroxyl group, the cleaning of the physically adsorbed alkoxide excessively, the activation by hydrolysis of the surface, is repeated so as to enable the serial laminating of oxide super-thin films of the fixed thickness. These techniques are expected to be the manufacture techniques for functionally graded material in which the composition distribution is controlled on a nano level. In this study, the growth of thin films by these techniques was examined in detail based on the measurement of the adsorption weight using a rock crystal vibrator. Additionally, the examination on the membrane structure and the mechanism of the thin film formation was carried out by SEM observation, XPS measurement, etc. The following is the result obtained in this study. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 177-182 傾斜機能材料のコンピュータシミュレーション Computer simulation of functionally graded materials 堂山昌男　木暮嘉明帝京科学大学 Y. Kogure and M. DoyamaTeikyo University of Science & Technology In the fields of space, aviation and energy science and technology, functionally graded material has been gathering attention as a material, which can be used in ultrahigh-temperature. Material used in high temperature must exhibit a function that eases thermal stress resulting from a steep temperature gradient of the thickness direction. For example, in order to establish a technology to design a functionally graded material in which the composition of metallic material and ceramic material is continuously graded, it is necessary to study the properties and optimum composition of atoms and molecules from a microscopic standpoint. The purpose of this study is to simulate a functionally graded material using molecular dynamics in an effort to obtain the basis for the optimal design. In order to simulate molecular dynamics, first of all, the interatomic potential must be obtained. Recently, it has been proven more clearly that the use of what is called pair potential is not a good idea in cases of use of metal and alloy. In the theory of the pair potential, it is assumed that the interaction of 2 atoms is given by the function only of the interatomic distance of 2 atoms. In fact, however, not only two atoms but also where other atoms are located is closely related to this matter. In other words, this problem should be handled as a many-body one. Actually, the potential decision procedure between different kinds of atoms has not yet been sufficiently established at present. This fiscal year, the many-body potential (Embedded Atom Potential) of pure metal should be clarified at first and then this will be expanded to include the potential between different kinds of atoms. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 183-188 傾斜機能誘電体基板 A Functionally Graded Substrate for Dielectrics 西田俊彦京都工芸繊維大学 Toshihiko Nishida,Kyoto Institute of Technology The remarkable development in the fields of aviation / space and communication / information of recent years has largely depended on downsizing and weight reduction of the electronic component device used in these fields. An important suggestion made for this field is with regard to the functionally graded dielectric constant type plane circuit substrate. It is that by changing the dielectric constant on the substrate in a graded manner, the corresponding printed wiring width can be freely controlled. That is to say, the line width printed on the substrate tends to be thinner and thinner corresponding to the higher dielectric constant and the lower dielectric loss of the high frequency substrate, but on the other hand, this thin line width has made the connection with external circuits difficult. Therefore, in case the dielectric constant can be changed stepwise from the central part to the peripheral part of the substrate and the line width of the circuit can be continuously controlled the smooth matching with the external circuits becomes possible. This study objective is to make clear and arrange the problems related to the above-mentioned dielectric constant functionally graded material and clarify the prospect of the basic science the process concerning this matter. The following is the content of the study that the research representatives have planned throughout the period. (1) The establishment of the basic scientific concepts - The establishment of the design concept of the graded functionalization of the dielectric substrate for high frequency circuits - The examination of the device theory and practical application performance (2) The examination of the functionally graded material process -The examination of the lamination sintering process by powder-metallurgical techniques - The examination of the simple lamination sintering process by brush coating methods - The examination of pressure sintering systems such as the hot forge method. (3) The evaluation of the material and properties - Dielectric property evaluation of functionally graded material - The property evaluation as a high frequency transmission substrate In the research for this fiscal year, though all the items on the above plan could not be investigated in detail, the examination on the main parts has been almost completed and the following is the report on it. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 189-194 傾斜機能圧電材料の研究 Studies on Functionally Graded Piezoelectric Material 谷順二東北大学流体科学研究所 Junji TaniTohoku UniversityInstitute of Fluid Science The application of piezoelectric ceramic has expanded to many fields and various electron devices such as actuators and transducers, and yet further performance enhancement, miniaturization and multi-functionalization are being required. By adopting the concept of "grading" in which the composition of multiple materials is continuously changed, it becomes possible to respond to the demand for multi-functionalization and performance enhancement, etc. This study aims at developing multifunctional and high-performance piezoelectric ceramic device by grading various piezoelectric materials as well as non-piezoelectric materials. To begin with, a calculation code which numerically analyzes the functionally graded piezoelectric material according to hierarchical models of micro, meso, and macro will be developed. As for the microscopic model, the lattice distortion by reverse piezoelectric effect is clarified in molecular dynamics, and for the meso model, the behavior of crystal grain and grain boundaries are clarified in discrete dynamics, and in the macro model, macroscopic deformation, strain, and stress are clarified in continuum mechanics (See Figure 1). Next, functionally graded piezoelectric material is fabricated in order to confirm the numerical simulation result, and the effectiveness of graded functionalization is confirmed. Electric field concentration inevitably appears on the edge of the electrode due to the operating of layered-type actuators, surface acoustic wave device and so forth. It has been strongly required to ease the stress concentration caused by this electric field concentration, to prevent destruction and to raise the fatigue strength, so that the functionality and reliability can be enhanced. Therefore, it was clarified that the graded functionalization was effective in the macro model this fiscal year. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 195-200 高機能磁性傾斜材料 High-Functional Graded Magnetic Material 松崎邦男、井上明久東北大学金属材料研究所 Kunio Matsuzaki and Akihisa InoueTohoku UniversityInstitute of Materials Research By grading the composition of materials of which the magnetic properties differ, each material can exhibit its superior characteristics so that more advanced functionality can be achieved. For example, there can be some cases of gradients from ferromagnetism to paramagnetism, from diamagnetism or superconductivity to perfect diamagnetism, and in the case of ferromagnetism, particularly, from hard magnetism to soft magnetism, etc. Moreover, by grading magneto-striction, a high-power actuator can be obtained. In the case of the combined material of hard magnetism and soft magnetism, spring magnets have been obtained by the exchange combination of a hard magnetism phase and a soft magnetism layer similar to the Fe-Nd-B system, and thus the functional improvement can be expected by grading of magnetism. In this study, by continuously changing compositions in the film pressure direction during vapor deposition using the electron-beam evaporation technique, films with graded magnetic properties were produced, and their organization and properties were examined. Additionally, a tape material with a graded structure produced by the liquid quenching technique will be discussed. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 201-206 積層ソフトフェライトの合成と磁気的特性 Synthesis and Magnetic Properties of Laminated Soft Ferrite 一ノ瀬昇早稲田大学理工学部 N. IchinoseSchool of Science and Engineering, Waseda University The miniaturization of the switching power supply, commonly contained in electronic equipment, seems to be an effective means for promoting the downsizing and space saving of the equipment. For this reason, a magnetic material is needed which has high saturation magnetization as a magnetic core, little loss, and high initial magnetic permeability at 500k-1MHz, the material currently in use (Mn-based ferrite) has large loss in the high frequency area so the above properties cannot be obtained. Additionally, the densification of electronic components has been demanded in response to the current miniaturization and weight reduction of the equipment. In order to produce the coil, which has ferrite as a magnetic core, roll lines are necessary, but the miniaturization has limitations. The chip inductor was developed to solve this problem. However, this too has some problems such as the change of magnetic properties by the inner residual stress. With the above in mind and to take a step for further miniaturization and weight reduction of magnetic material, the following was studied. Some of the main properties of soft magnetic material (soft ferrite), which contains Fe2O3 as a main component, are high permeability, saturation magnetization, low loss and so forth. (Ni1-x-Znx) Fe2O4 is one of the most typical soft ferrite. This experiment was conducted with a purpose of making a laminated body in which the above value x gradually changes so as to produce Ni-Zn ferrite which shows high Curie temperature while keeping relatively high saturation magnetization. In the mean time, the combination of each layer's composition as well as the thickness of each layer were changed, and the temperature characteristics of the magnetization on these cases were examined. In addition to Ni-Zn ferrite, there is another type of typical soft ferrite, Mn-Zn ferrite. As mentioned above, a laminated body which had combined Ni-Zn ferrite with Mn-Zn ferrite was produced and that magnetism was also examined. The synthetic method employed in the above case was the ordinary solid phase method, but a spark plasma sintering machine was introduced this time so the synthesis of the lamination soft ferrite was attempted using this equipment as well. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 207-212 傾斜機能材料の電気的・磁気的性質「傾斜機能磁性薄膜」 Electric and Magnetic Properties of Functionally Graded Materials- Functionally Graded Magnetic Thin Films 本間敬之早稲田大学理工学部 T.HommaDepartment of Applied Chemistry, School of Science and Engineering, Waseda University The magnetic recording system using magnetic thin films has been supporting the basis of the advanced information society as the center of data storage equipment. Its recent rapid progress is premised on the storage and high speed transfer of large-capacity data, and it is urgent to realize more advanced magnetic recording systems. For example, in the case of magnetic recording medium, the surface recording density of a current hard disk medium has reached 1.44 Gbits/inch2 on the mass production level, and it will reach the order of 10 Gbits/inch2 in several years. Since the bit size is less than 1micrometer**2 in such an ultra-high density recording system, the micro structure control on a crystal level is required for the control of such medium properties. We have produced a medium thin film suitable for the vertical magnetic recording system-capable of the next generation ultra-high density recording-by electrochemical techniques, and systematic examination for it has been carried out. As a result, it has been found that the magnetic properties are greatly improved by the property control of the recording medium film thickness direction. The head magnetic field intensity attenuates in inverse proportion to the distance, and as it penetrates the medium thin film, it is greatly influenced by the magnetic permeability. Therefore, in order to carry out stable and high-density recording, the magnetic property control of the medium film thickness direction in the sub micrometer order, at the same time, taking into consideration the head field distribution at the time of recording, is important . That is to say, in case the lamination of thin films with different magnetic properties-the medium with continuously graded magnetic properties in proportion to the change of the recording magnetic field, instead of the stepwise property change-is used, large improvement in the magnetization (recording) efficiency as well as the stabilization of the residual magnetization condition can be expected, resulting in major medium property improvement. This study, based on the above, intends to carry out the manufacture and evaluation of thin films with the graded magnetic functions in the film thickness direction and then to clarify its effectiveness. While the general material design guidelines for graded magnetic characterization of thin films by this technique were clarified first of all, the basic examination along with it was undertaken this fiscal year. The following is the results. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 213-218 溶融塩反応を利用した組成傾斜BaTiO3複合粒子の作製と相転移挙動 Fabrication of graded composite particles of BaTiO3 and the phase transitional behavior thereof by means of molten salt reaction 嶋田志郎北海道大学工学部 Shiro ShimadaGraduate school of Eng., Hokkaido University The BaTiO3 ferroelectrics have a Curie temperature of 130 deg.C and are widely used as capacitors. The BaTiO3-PbTiO3 ceramics are a better candidate for high temperature use as capacitors in comparison to BaTiO3. Development of dielectric ceramics with a wide temperature range that can control the aforementioned composition is greatly anticipated. Thus far, it has been reported that the molten salt replacement reaction proceeds as the following equation indicates, between metal chlorides and BaTiO3 (1) BaTiO3 + MCl2 -> MTiO3 + BaCl2 (1) (M=Ca, Sr, Co, Ni, etc.) This reaction results when the size of the M2+ ion is smaller than the Ba2+ ion. By utilizing the low melting point of PbCl2 (498deg.C), the authors have created a reaction between the molten salt PbCl2 and BaTiO3, and composed a powder from the (Ba, Pb)TiO3 solid solution with the desired composition. BaTiO3 + PbCl2 -> (Ba, Pb) TiO3 + (Ba, Pb) Cl2 (2) If adequate conditions are selected here, we have concluded that a core-shell composite grain with the core and shell of (Ba, Pb) TiO3 co-existing in each grain. Since the existence of this graded composition is difficult to determine from a composite grain, attempts were made to confirm the existence of such in a core-shell structure that is formed through a molten reaction using sintered BaTiO3. In this study, we established the conditions of the BaTiO3 - (Ba, Pb) TiO3 grain composition through the molten reaction of BaTiO3 and PbCl2. By clarifying the mechanisms of the above process and by controlling the reaction, we researched whether or not it is possible to form a graded composition within the core-shell BaTiO3 - (Ba, Pb) TiO3 grain. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 219-224 レーザ・デポジション法による傾斜機能固体電解質薄膜の作製と評価 Fabrication and evaluation of functionally graded thin film on solid electrolytes using the laser deposition method 湯上浩雄　内藤均東北大学工学部 Hiroo Yugami, and Hitoshi NaitoGraduate School of Engineering, Tohoku University Yttria-stabilized zirconia (YSZ) and other oxygen ion conductors can have useful application as solid electrolyte in energy conversion systems. The charge carriers within the solid electrode are ions, whereas the charge carriers in the external circuit are electrons. Therefore, at the present, porous material with high electronic conductivity is used as electrodes, but in this case the electrode reactions occur at all three interfaces of electrolyte, electrode and vapor phases. In addition, by continuous running, we run into the problem of electrode deterioration such as the decline in the 3 phase interfaces. In order to improve power generation effectiveness, we need to expand the area of reaction and stabilize the structure. In order to do so, it is desirable that mixed electronic and ionic conductor is used as electrodes. Also, because these materials will be used in high temperature and the joining of electrolytes and electrode material involves the joining of two solids, it is necessary that the interfaces of both be consistent. From this perspective, if YSZ is used as electrolyte for SOFC, good adherence can be achieved by using a zirconia-based mixed conductor as an electrode, and the use of single component solid oxide fuel cell has been proposed 1). To improve electronic conductivity in zirconia-based mixed conductor, higher concentration of dopant, which promotes electronic properties, such as thermal expansion coefficient, occurs between electrolyte and electrode. To overcome this problem, we applied functionally graded materials (FGMs) to the electrode in which the dopant concentration in the electrode is gradually changed from gas/electrode interface (high dopant concentration) to electrode/electrolyte interface (low concentration). There have been reports on functionally graded porous NiO-YSZ electrode 2) at the fuel side and In2O2-ZrO2 air-side electrode3, but the novelty of our idea is to used the mixed conductor so as to keep its crystal structure while grading the function and also to keep fine commensurate structure in terms of physical and electrochemical properties. In this study, the fabrication of functionally graded CeO2-YSZ thin film by laser ablation method is discussed, and its structure and electrical properties are evaluated in order to optimize the fabrication process. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 225-230 広帯域超音波トランスジューサ実現のための圧電傾斜機能材料の基礎的研究 Basic Research of Piezoelectrically Graded Materials for Broadband Ultrasound Transducers 中村僖良　山田顕　本郷哲東北大学工学部通信工学科 K. Nakamura, K. Yamada, S. HongoTohoku UniversityElectrical Communication Engineering,Faculty of Engineering Ultrasound transducers have widely used in various fields of ultrasonic measurements and/or imaging such as nondestructive evaluation and medical evaluation. In these fields, high resolution capability and wide frequency band are required, and the realization of broadband ultrasound transducers is an important issue. Conventional ultrasound transducers use a piezoelectric plate in which the polarization and piezoelectric constant are uniform. In such cases, the stimulus, which is proportionate to the differential of the location of the piezoelectric constant, concentrates on both surfaces of the piezoelectric plate. Therefore, when impulse voltage is impressed upon such transducers, pulse waves from both surfaces of the piezoelectric plate is stimulated, making the generation of short single pulses impossible. This results in a narrowband frequency, as expressed by Fourier conversion of the impulse response, and the center frequency becomes highly dependent on the dimensions of the piezoelectric. Recently, the authors group has come up with the idea of broadband ultrasound transducer with graded piezoelectric parameters in which the grading of the polarization within the piezoelectric plate in the thickness direction. In other words, if the piezoelectric parameter in a plane transducer could be faded out between one face and the other, there would only be one acoustic pulse corresponding to the larger gradient of the piezoelectric stress at one surface. Therefore, as the first step of research for this year, we endeavor to 1) establish the fabrication method of graded piezoelectric parameter and 2) Study graded transducers with composite V-groove structure in order to acquire fundamental knowledge for the trial manufacture and testing of broadband ultrasound transducer using a graded piezoelectric parameter. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997 2 1997-03-01 231-236 組成傾斜化による広温度域高誘電性材料の開発 Development of High Dielectric Material for Wide Temperature Range by Composition-Grading 島田昌彦　山根久典　内田聡＊　窪田俊一　滝沢博胤＊＊東北大学素材工学研究所＊東北大学反応化学研究所＊＊東北大学大学院工学研究科 M. Shimada, H. Yamane, S. Kubota, S. Uchida＊, H. Takizawa＊＊Institute for Advanced Materials Processing, Tohoku UniversityInstitute for Chemical Reaction Science, Tohoku University＊Tohoku University＊＊ The ceramic condenser is characterized by properties such as capacities, temperature coefficient, dielectric loss (quality factor Q=1/tan) shown by tan(dielectric loss tangent), etc. Among such ceramic condensers, the ones classified as temperature compensation condensers exhibit almost a rectilinear static capacitance change for the temperature and they have a temperature coefficient of -4700~+100ppm/deg.C. Though their specific inductive capacity (epsilon)r is small being from 6 to 650, the value of Q can be as large as 1000-8000, so they are used for general circuits. As raw materials, solid solution or composite system ceramics such as titania (TiO2), titanic acid magnesium (MgTiO3) and 2MgOSiO2-SrO-BaO-TiO2, etc. are used. As for the high dielectric constant ceramics condenser, though the dielectric constant is high being 3000-7000, Q is small, from 20 to 100 so it is used as a bypass condenser. This condenser utilizes the high dielectric constant in the vicinity of the phase transition temperature (the Curie temperature: up to 120deg.C) of the barium titanate (BaTiO3) ferroelectrics. The phase transition temperature can be moved to the vicinity of room temperature by the addition of shifters such as SrTiO3 and CaSnO3, and also, in order to level off the temperature characteristics, depressors such as CaTiO3 and MgTiO3, which decrease dielectric constant peaks, are added so that the electric permittivity change around the room temperature would be kept within 10%. For both the temperature compensation ceramic condensers and the high dielectric constant ceramics condensers, to control their properties, uniform addition and combination of the second phase have been conducted. This study aims at controlling the temperature properties of dielectric constant by graded composition so as to develop dielectrics with high dielectric constant as well as ones with various temperature coefficients in a wide temperature range, which has been difficult for the conventional uniform addition and homogeneous dispersion composite materials. Japanese