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[3rd International Symposium on Structural and Functional Gradient Materials　FGM'94　PROCEEDINGS (pp.495-711)](https://mdr.nims.go.jp/datasets/09908bbf-902b-4cf4-81e7-3845de056c8f)

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Sheet1 BookTitle_j BookTitle_e Volume/Issue Issueddate Page Title_j Title_e AuthorList_j AuthorList_e Abstract Language 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 495-501 窒化ケイ素と、Si3N4/TiN CMCおよびTiN/Ni MMC積層を用いた超合金との間の組成傾斜 COMPOSITIONAL GRADATION BETWEEN SILICON NITRIDE AND SUPERALLOYS USING Si3N4/TiN CMC AND TiN/Ni MMC LAYERS R.Larker and T.BeckmanDivision of Engineering Materials Lulea University of Technology, Sweden R.Larker and T.BeckmanDivision of Engineering Materials Lulea University of Technology, Sweden  Graded Si3N4/TiN CMC and TiN/Ni MMC have been prepared by HIP for a joint piece concept, aimed at reducing residual stresses between Si3N4 and lncoloy 909, as a part of a Brite/EuRam project concerning development of Graded Structures. To reduce the CTE mismatch between graded CMC and MMC joint pieces, the CTE at the TiN-rich side of the graded MMC should be as close as possible to that of pure TiN. Due to abnormal grain growth in the superalloy at higher temperatures, the HIP temperature for simultaneous joining and densification in the solid state of the TiN/Ni MMC is limited to 980deg.C. Regarding layers with low Ni matrix content, it was there-fore considered necessary to develop powder preparation methods giving useful relative density and strength levels after HIP for minimized Ni contents and CTE levels. Ni-coated TiN powders has shown useful for this purpose, and results concerning densities and microstructures of TiN/Ni MMC materials, as well as CTE behaviour of relevant Si3N4/TiN CMC and TiN/Ni MMC compositions, will be presented. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 503-508 連結ケイ素基材セラミックスへの過渡的FGMアプローチ A TRANSIENT FGM APPROACH TO JOINING SILICON-BASED CERAMICS B.J.Dalgleish, A.P.Tomsia and A.M.GlaeserUniversity of California, Berkeley, California, USA B.J.Dalgleish, A.P.Tomsia and A.M.GlaeserUniversity of California, Berkeley, California, USA  A multilayer metallic interlayer consisting of a thin Cu-Au alloy cladding on a thicker pure Ni core layer was used to form Si3N4/Ni/Si3N4 and SiC/Ni/SiC bonds at 950`C. The thin cladding layer forms a transient liquid phase to allow joining at low temperatures avoiding excessive reaction. The relatively thicker core of a higher melting point material dominates the physical properties. Ideally, the interlayer's functional gradient disappears during processing, yielding a homogenized interlayer with the potential for high-temperature service. In both cases, the maximum room temperature four-point bend strengths approached those of the parent ceramic material. Results of fractographic and microchemical analyses provide the basis for discussing aspects of the interlayer chemistry, processing conditions, and ultimate mechanical properties. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 511-517 流動床(層)条件下での、傾斜機能コーティングの浸食 THE EROSION OF FUNCTIONALLY GRADED COATINGS UNDER FLUIDISED BED CONDITIONS G.R.Heath 1, M.M.Stack 2, M.Rehberg 2 and P.A.Kammer 11 Eutectic+Castolin Group, Research & Technology Center, Lausanne, Switzerland 2 Corrosion and Protection Centre, UMIST, Manchester, UK G.R.Heath 1, M.M.Stack 2, M.Rehberg 2 and P.A.Kammer 11 Eutectic+Castolin Group, Research & Technology Center, Lausanne, Switzerland 2 Corrosion and Protection Centre, UMIST, Manchester, UK  Although there have been recent studies on the erosion and wear of bulk metal matrix composites, there has been little wear work on the related group of materials, functionally graded materials (FGMs), particularly as coatings. Because such materials provide a gradation in properties such as hardness and thermal expansion coefficient between the coating and the substrate, it is thought that they may have potential in aggressive environments such high temperature energy conversion processes (resisting spallation and erosion).       In a low velocity fluidised bed erosion environment the effects of erodent particle size and bed temperature on the erosion rate through the section of a functionally graded coating was studied. The coating consisted of a varying fraction of WC particles (0- 42 vol. %) in a Ni-Cr-based self-fluxing matrix. The FGM coating was developed via a new, industrial route based on flame spraying. The erodent particle size varied from 200 mm to 600 mm, testing was at 25deg.C and 600deg.C, and the impact angle was 90 deg.. The erosion rate was at a minimum at an intermediate vol. % WC and increases with increasing temperature. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 519-524 傾斜構造における耐摩耗被膜 WEAR RESISTANT COATINGS WITH GRADED STRUCTURE H. Berns and W. TheisenInstitute for Materials, Ruhr-University of Bochum, Germany H. Berns and W. TheisenInstitute for Materials, Ruhr-University of Bochum, Germany  Wear resistant surface layers with a functional gradient are produced by thermal spraying and powder metallurgy embedding hard phases in a metal matrix with a hard phase content raising gradually towards the surface. Hardness, bending strength, wear resistance, crack propagation, cohesive strength and thermal cycling are investigated and related to the microstructure. The graded structures have advantages over coatings with a constant hard phase content. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 525-531 溶接による耐摩耗傾斜材料の表面蒸着 SURFACE DEPOSITION OF WEAR RESISTANT GRADED MATERIALS BY WELDING M.Blank-Bewersdorff, H.Luscher and A.RosseletSulzer Innotec Ltd., Winterthur, Switzerland M.Blank-Bewersdorff, H.Luscher and A.RosseletSulzer Innotec Ltd., Winterthur, Switzerland  There is an increasing need in industry for wear and corrosion resistant components. Therefore those parts which have to withstand the most severe attacks are often cladded with a higher resistant material. However, hard facing often creates problems due to cracking in or near the interface. This is originated in the different properties of each material. The introduction of an intermediate layer, which is able to create a smooth or at least a stepwise transition of the relevant properties, might reduce the cracking tendency. This paper presents the first results of a study about the introduction of a buffering layer in the hard facing process of a valve steel. For the deposition process plasma transferred arc welding was employed using different welding parameters. A careful metallographic examination as well as microanalysis and microhardness measurements were performed. The results reveal that the cooling rate is the main influencing factor, which determines the gradient of dilution.  In parallel, an approach to calculate the residual stresses was started. The first calculations give the stress distributions depending on welding velocity of Stellite cladded 21 Cr Mo V 5 7 when no buffering layer was used. The calculations show that the assumptions used for the modelling are not yet sufficient to describe the experimental results. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 533-539 モリブデン付加ステンレススティールの表面レーザー融解 SURFACE LASER MELTING OF STAINLESS STEEL IMPLANTED WITH MOLYBDENUM L.Beaunier 1, F.Pillier 1,R.Fabbro 2 and P.Laurens 21 university of Paris VI2 Laboratory of applications of power lasers UMR 114 CNRS, France L.Beaunier 1, F.Pillier 1,R.Fabbro 2 and P.Laurens 21 university of Paris VI2 Laboratory of applications of power lasers UMR 114 CNRS, France  The topic of our research is the fundamental study of functional metallic materials in order to improve mechanical and corrosion properties We have used a conventional 304 stainless steel enriched with molybdenum in the surface by a laser process. Microstructural parameters, mixing of elements and susceptibility to corrosion of resultant materials are performed by transmission electron microscopy, TEM - STEM high resolution X-ray spectrometry analysis and classical electrochemistry. The surface treatment of stainless steel is obtained, in a first time, by implantation with ions of molybdenum at 100 keV. We observe a surface phase transformation from austenitic to ferritic phase with 0,3 micrometer grain size and a supersaturated solid solution up to 18 weight percent molybdenum in near surface region with a gaussian profile up to only 60 nanometers. In order to have a more important surface layer with lower molybdenum concentration, surface melting is applied by a high energy laser beam. In this way, we could obtain quenching rates greater than those that are achieved by conventional methods and rises to nanostructural features with composition gradient. We discuss also results on structure and composition of laser melting of surfaces formed by molybdenum deposited in high temperature baths of molybdenum salts.       Keys words: laser melting, ion implantation, corrosion, electrochemistry, transmission electron microscope, X ray analysis, Rutherford Backscaterring. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 541-547 Sic/C 傾斜複合材料に関連して新たに開発されたグラファイト材料特有の特性評価 EVALUATION OF CHARACTERISTIC PROPERTIES OF A NEWLY DEVELOPED GRAPHITE MATERIAL WITH A SiC/C COMPOSITION GRADIENT 藤井貴美夫、中野純一、新藤雅美日本原子力研究所  茨城県那珂郡東海村 K.Fujii, J.Nakano and M.ShindoJapan Atomic Energy Research Institute, Tokai-mura, Naka-gun, Ibaraki-ken, Japan  In order to evaluate the characteristic properties of advanced SiC/C compositional gradient graphite materials, which consist of a SiC surface coating, intermediate SiC/C layer and graphite matrix, a thermal cyclic oxidation test in an oxidative environment at high temperatures and a bending test at room temperature were carried out together with comparative SiC coated graphite materials. It was found that the developed materials exhibited an excellent oxidation resistance under severe thermal cyclic conditions, and that the strength was about the same as that of SiC coated graphite and higher than that of the substrate graphite. Furthermore, the thermal cyclic resistance and the bending strength of the gradient materials were independent of the Si contents in the intermediate SiC layers. These findings are discussed on the basis of the beneficial effect of the intermediate SiC-graphite gradient layer with respect to oxygen penetration. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 549-554 傾斜相を有するCr-C システム母材への保護材料 PROTECTIVE MATERIALS ON THE BASE OF THE Cr-C-SYSTEM WITH PHASE GRADIENT G.A.Domrachev, V.A.Varuhin and A.A.ZakurazhnovOrganometallic Institute of the Russian Academy of Sciences Kiev, Ukraine G.A.Domrachev, V.A.Varuhin and A.A.ZakurazhnovOrganometallic Institute of the Russian Academy of Sciences Kiev, Ukraine  A new technology to prepare protective and wear-resistant chromium carbide coating for metal surface strengthening has been developed at the Organometallic Institute and is applied in Russia. The method of preparing coatings consists in vapour-phase plating by decomposing organometallic compounds of chromium. The most convenient and easy way to manufacture compounds are liquid bis-arene-chromium (0) derivatives based on ethyl benzene homologues which have been prepared on an industrial scale.       The decomposition of organochromium liquid vapour proceeds on the work piece surface which is heated to form the solid phase of chromium carbide, Cr7C3 or chromium.       The process can be controlled and regulated so that the chromium carbide deposition alternates automatically with that of metallic chromium. This results in formation of micro composite or laminar coating: chromium carbide - chromium with alternating composition. Such coatings possess unique properties (their wear resistance is twice that of hard-alloyed materials on the basis of WC-Co, which have the same hardness).       The protective coatings, prepared by the present technology, have obvious advantages over chromium electroplating when used to protect the friction and working surfaces of steel components of irregular or complex shape owing to their hardness, corrosive and wear resistance, anti friction properties, as well as the absence of open porosity even with small coating thickness. Also, this process is ecologically pure and readily automated. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 555-560 WC-CO 母材傾斜材料加工の拡張的研究 DILATOMETRIC STUDY OF THE PROCESSING OF WC-Co BASED GRADIENT MATERIALS N.Favrot 1, 2, C.Colin 1, 2, J.Besson 1 G.Barbier 3 and F.Delannay 21 Ecole des Mines de Paris, Centre des Materiaux, Evry, France. 2 Univesite Catholique de Louvain-La-Neuve, Louvain, Belgique. 3 Cerametal, Luxembourg. N.Favrot 1, 2, C.Colin 1, 2, J.Besson 1 G.Barbier 3 and F.Delannay 21 Ecole des Mines de Paris, Centre des Materiaux, Evry, France. 2 Univesite Catholique de Louvain-La-Neuve, Louvain, Belgique. 3 Cerametal, Luxembourg.  The aim of this work was to investigate the processing conditions making possible the obtention of composition gradients into cemented carbide parts. Indeed, graded structures consisting of a hard surface on a tougher bulk should improve the performances and/or life time of drilling tools. Multilayerd green bodies were prepared by cold pressing a stacking of powder layers containing different Co contents ranging from 10 to 30%. Two sintering methods have been studied: solid state sintering and liquid phase sintering. Solid state sintering allows to maintain the original composition profile into the successive layers, but it does not allow to reach complete densification without a post-hipping treatment. During liquid phase sintering, the migration of the liquid through the structure brings about a decrease of the composition discontinuity between the successive layers. In order to elucidate the driving forces governing the phenomenon, different schemes of processing involving a succession of liquid phase sintering with different dwell times have been investigated. The composition gradients were monitored by measuring the hardness profile in the vicinity of the interfaces between the layers. As hardness values could be also influenced by grain growth, these measurements were completed by microprobe analysis. Successive sections parallel to the interfaces were also characterized from the point of view of density, and the Co content and the microstructure of the sections was studied by magnetic measurements. Tribologic tests against rocks were carried out in order to compare the wear resistance of composition gradient cermets and of homogeneous cermets. Comparison was also made of the temperature reached by these two types of materials during such wear tests. Finite elements computations allowed to predict the temperature reached at the interface between the tool and the rock. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 561-567 傾斜WC/Co 材料の液相燒結 LIQUID PHASE SINTERING OF GRADIENT WC/Co MATERIALS N.Desmonts, M.Cans, N.Cherradi and B. IschnerSwiss Federal Institute of Technology, Lausanne, Switzerland N.Desmonts, M.Cans, N.Cherradi and B. IschnerSwiss Federal Institute of Technology, Lausanne, Switzerland  Liquid phase sintering of homogeneous WC-Co composites is a well known industrially viable process leading to high-density cemented carbides on a large scale. The same process fails however to yield satisfactory results with graded specimens: in this case an homogenization is observed. Graded samples can only be obtained by solid state sintering below 1300deg.C which takes longer time and results in lower density. By numerical simulation of the process, it can be shown that this effect is due to the unusually high difference in solubility of WC in solid and liquid Co. Experimental results and model calculations will be presented. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 569-574 WC/Co 二層成形体における圧粉強度 GREEN STRENGTH OF WC/Co BILAYER COMPACTS C. Colin 1,2, N. Favrot 1,2, F. Li 1 and G. Barbier 2.1 Catholic University of Louvain, PCIM/MAPR, Belgium2 Materials Center of P.M. FOURT, E.N.S.M.P., France3 Cerametal SA, Mamer, Luxembourg. C. Colin 1,2, N. Favrot 1,2, F. Li 1 and G. Barbier 2.1 Catholic University of Louvain, PCIM/MAPR, Belgium2 Materials Center of P.M. FOURT, E.N.S.M.P., France3 Cerametal SA, Mamer, Luxembourg.  The aim of this work is to assess the green strength of bi-layer structures by the diametral - compression test. The results are discussed in terms of the WC grain size, difference of compaction pressure between the layers, and composition discontinuity across the interface. After cold pressing, the two-layer stack must present a sufficient interfacial strength to withstand to the mismatch of the shrinkages between the layers during sintering. This mismatch of the shrinkages must also be minimized in order to minimize the macroscopic deformation of the sample during the sintering. This phenomenon can be controlled by using different compaction pressures between the layers. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 575-579 WC/Co 傾斜機能材料の合成と特性評価 PROCESSING AND CHARACTERIZATION OF WC-Co FUNCTIONAL GRADIENT MATERIALS M.M.GasikHelsinki University of Technology, Espoo, Finland M.M.GasikHelsinki University of Technology, Espoo, Finland  The WC-Co functional gradient materials (FGM) have been fabricated by powder metallurgy and infiltration technique. The microstructure and properties of the specimens have been studied and used as initial entries for quantitative analysis of these materials. The wave let reduction method and image processing were applied for computation of phases distribution and their volume fractions. The micromechanical model was used to calculate the basic properties of hard FGM, such as modules and thermal characteristics. For structure-sensitive properties (e.g. hardness), a semi-quantitative model was developed and respective surfaces of hardness distribution in the specimens were drawn. The calculated and measured values are comprised with other known approaches for hard materials. Different fabrication techniques for hard FGM production are also discussed. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 581-586 WC-CO 傾斜材料：熱流束測定と評価 WC-CO GRADED MATERIALS: HEAT FLUX MEASUREMENTS AND ESTIMATION N. Cherradi 1、N. Desmonts 1、川崎亮 21 Swiss Federal Institute of Technology Lausanne, Switzerland 2 東北大学　仙台市 N. Cherradi 1, N.Desmonts 1 and A. Kawasaki 21 Swiss Federal Institute of Technology Lausanne, Switzerland 2 Tohoku University, Sendai, Japan  Graded materials components of 25 by 14mm surface and 2 to 3 mm thickness exhibiting a continuous evolution from 5 to 25wt.% of cobalt content have been prepared by the powder metallurgy route. A description of the process and the characterization of the microstructure of the sintered materials are given.       A temperature difference was imposed on the samples by heating the upper surface, while the bottom surface was cooled. The temperature distribution was measured and compared with the estimated values obtained by analytical calculations. The influence of composition profile and thickness of the graded structure were investigated. It was found that the temperature distribution shows a characteristic change with the composition. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 587-592 傾斜硬質材料の製造と特性 FABRICATION AND PROPERTIES OF GRADIENT HARD METALS V. RichterFraunhofer-Institute of Ceramic Technologies and Sintered Materials, Dresden, Germany V. RichterFraunhofer-Institute of Ceramic Technologies and Sintered Materials, Dresden, Germany  Manufacturing gradient hardmetals versus dry pressing has been investigated including WC-Co hardmetals with binder contents between 5,5 wt.-% and 11 wt.-%and different grain size and several steel-cutting grades. Particular attention was paid to the cobalt transport during sintering. The mechanisms controlling the transport of cobalt during liquid phase sintering were elucidated. A mathematical model to describe this process was developed. Furthermore, the influence of thermal stresses occurring after cooling from sintering temperature on the room-temperature properties were investigated. The fatigue strength was shown to be significantly improved by thermal stresses. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 593 「傾斜構造」概念の鉱業用工具への応用 THE APPLICATION OF THE "GRADE STRUCTURES" CONCEPT TO MINING TOOLS G.P.Yiasemides and I.B.MacCormackCeram Research, U.K. G.P.Yiasemides and I.B.MacCormackCeram Research, U.K.  The "Graded Structures" concept has been applied to the fabrication of multipurpose tools for earth removal operations. Three dimensional components have been constructed incorporating a graded zone between the hard, wear-resistant surface of the tool and its tough core. The main aim of the work, outlined in this paper, was to develop the technologies required to adopt the "Graded Structures" concept and apply this to real size and shape components which could be tested under service conditions. Powder metallurgical techniques were used to construct both materials and components. The synthesis of powders to achieve the required compromise between properties and fabricability, in three dimensional geometries, using the Metal Injection Moulding (MIM) process and the subsequent consolidation by Hot Isostatic Pressing (HIP) technique to produce the final artifact will be discussed. Emphasis will be placed on the processing technologies and their interaction with the properties at each stage. In this study use was made of tungsten carbide cobalt cermets whose matrix was diluted either by increasing the cobalt binder or blending ferrous base compositions to match the proportions of the rest of the tool and achieve the required transition between hardness and toughness. The work discussed in this paper is part of a collaborative study funded by the European Commission under the Brite-Euram framework (contract No. BREU-CT91-0428). English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 594 傾斜TiCサーメット切削工具の製作と特性 PREPARATION AND PROPERTIES OF GRADIENT TiC CERMET CUTTING TOOLS C.F. ClineLawrence Livermore National Laboratory, Livermore, U.S.A. C.F. ClineLawrence Livermore National Laboratory, Livermore, U.S.A.  The success of earlier work on "Gradient Armor" by Cline and co-workers [1] focused our effort to develop gradient cermets for cutting tool and rock drilling applications. The same set of material properties that made a good armor are also in demand for cutting tools, particularly in the area of interrupted cuts where the loading is intermittent.       The cutting tools were fabricated from cermets of TiC-NiMo wherein the percentage of TiC ranged from 95% TiC at the top surface, transitioning to an 86% TiC and then to steel at the back surface. The bonding between the segments was achieved by brazing each segment to the other and then joining the graded section to the steel by brazing. A series of machining tests were carried out wherein the tests emphasized interrupted cuts. The successful results demonstrated that enhanced performance could be obtained using the gradient concept to avoid damaging tensile loads. [1] U.S. Patent number 3, 743, 569, July 1973. *This work was performed under the auspices of the US. Department of Energy by the Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48 English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 595 PVD 法により製造された機能及び組成傾斜切削刃 FUNCTIONALLY AND COMPOSITIONALLY GRADED CUTTING EDGES PRODUCED WITH PVD METHODS E. BergmannWear Protection, Balzers, FL E. BergmannWear Protection, Balzers, FL  Several types of graded coatings for the cutting edges of tools have been developed recently. They comprise the coatings where carbide/nitride content is varied from substrate interface to the surface and coatings, where nitrides of different metals are alloyed with graded compositions. For special applications bi-functional coatings are used, which are built from antigalling hard coatings like titanium nitride and self lubricating medium hard coatings like the WC/C coatings. WC/C coatings are a material, where a diamond like carbon matrix is strengthened by the incorporation of sized b-WC crystals.    The influence of the graded structure on the performance of high speed steel and cemented carbide cutting tools is compared for drilling and milling operations. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 601-605 高性能エネルギー変換材料についての企画研究 PROJECTED RESEARCH ON HIGH-EFFICIENCY ENERGY CONVERSION MATERIALS 1、新野正之２、小泉光恵1 航空宇宙技術研究所　角田宇宙推進技術研究センター　　宮城県角田市2 龍谷大学　滋賀県大津市 M. Niino 1 and M. Koizumi 21 National Aerospace Laboratory, Kakuda Research Center Kakuda City, Miyagi 2 Ryukoku University, Otsu City, Siga, Japan  This paper outlines the research plans of the national project entitled, "Development of Energy Conversion Materials through Formation of Gradient Structures", with the special coordination funds for promoting science and technology from the Science and Technology Agency of Japan. This program contains efforts on improvements of energy conversion efficiency by introducing gradient structure into energy conversion materials including thermoelectrics and thermionics. The final goal was set at developing a high-efficiency hybrid direct energy conversion system (HYDECS). In order to promote the program efficiently, an organization was structured of five technical groups: Material design, Thermoelectric conversion, Thermionic conversion, Elements & processing, as well as Characteristics evaluation. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 607-612 タンデム熱電気素子の変換効率の評価 EVALUATION OF CONVERSION EFFICIENCY OF TANDEM THERMOELECTRIC DEVICES A.Koyanagi  林原光男株式会社日立製作所 A.Koyanagi and M.HayashibaraEnergy Research Laboratory, Hitachi, Ltd., Japan  A simulation program to evaluate conversion efficiency of thermoelectric devices has been developed. The program can take into account the temperature dependence of the thermoelectric properties of materials, Thomson and Peltier effects and Joule heating. Effects of radiation heat transfer from the side surface of a device are also contained in the solution. Using the program, a 3-stage tandem thermoelectric module that consisted of SiGe, PbTe and BiTe devices was designed. On the condition that thermal input and hot and cold junction temperatures were fixed, the length of each device in the module was determined in order to maximize its conversion efficiency. Radiation heat loss has been reduced to one tenth by a shield around the module. The cross sections of the devices and the numbers to be connected in series and parallel circuits in the three stages were optimized so as to enable all devices to generate electric power at their maximum conversion efficiency, and at the same time, to minimize the heat loss through lead wires, and to supply the whole power output to one load. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 613-618 高ホウ素含量のシリコン・ホウ素化合物の合成と熱電特性 SYNTHESIS AND THERMOELECTRIC PROPERTIES OF SILICON-BORON COMPOUNDS WITH HIGH BORON CONTENTS 陳立東1　後藤孝 2　向田雅一 3　新野正之 1　平井敏雄 21 航空宇宙技術研究所　角田宇宙推進技術研究センター　角田市2 東北大学金属材料研究所　仙台市3 化学技術研究所　　つくば市 L.Chen 1, T.Goto 2, M. Mukaida 3, M.Niino 1 and T. Hirai 21 National Aerospace Laboratory, Kakuda Research Center, Kakuda2 Institute for Materials Research, Tohoku University, Sendai3 National Chemical Laboratory for Industry, Tsukuba, Japan  Boron-rich silicon borides were prepared by arc-melting and spark plasma sintering. The thermal conductivity (kappa), electrical conductivity (sigma) and Seebeck coefficient (alpha) were measured in a temperature range of 400-1200 K, and the dimensionless thermoelectric figure of merit ZT (ZT = (alpha)2(sigma)T/(kappa)) was evaluated. The ZT values for all the specimens increased with increasing temperature in the considered temperature range. Large Seebeck coefficient and ZT values (900 mV K-1 and 0.2 at 1100 K, respectively) were achieved for the plasma sintered silicon boride containing 90at% B, which consisted of SiB14 and SiB6 phases. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 619-625 宇宙発電器のためのFGM基材直接エネルギー変換システムの性能解析 PERFORMANCE ANALYSIS OF FGM-BASED DIRECT ENERGY CONVERSION SYSTEM FOR SPACE POWER APPLICATIONS 江口邦久1, 星野健 2　藤原勉 21 宇宙開発事業団 (NASDA)　　つくば市2 航空宇宙技術研究所　　東京都 K.Eguchi 1, T.Hoshino 2 and T.Fujihara 21 National Space Development Agency of Japan (NASDA), Tsukuba 2 National Aerospace Laboratory, Tokyo, Japan  An analytical investigation of space solar power conversion technology using functionally gradient materials (FGM) for direct conversion of heat to electricity, was initiated in April of 1993. The high efficiency power plant under consideration is a hybrid direct energy conversion system (HYDECS) with a cascaded configuration of cesium-filled thermionic and thermoelectric converters (TIC/TEC). The system may provide a capability of conversion efficiency above 40 percent with a heat sink temperature of 300 K. In the present thermodynamic calculations, a simplified model for static power generation is applied. In the model the TIC power in a topping mode is computed by an iterative routine to meet an energy balance for an assumed barrier voltage and limited back emission from the collector. On the other hand, TEC power in a bottoming mode at lower temperatures is evaluated for a given heat loss along a figure of merit (Z) curve. Furthermore, a radiative heat transfer from a heat source to the TIC emitter, and a heat pipe interface for heat transfer between the TIC and the TEC, is incorporated in the power system design. The present paper describes the HYDECS performance evaluation analysis, and provides the significant considerations for its design requirements. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 627-632 高性能シリコン・ゲルマニウム熱電電池用FGM柔軟パッド設計 FGM COMPLIANT PAD DESIGN FOR HIGH EFFICIENCY SILICON GERMANIUM THERMOELECTRIC CELL 神戸満, M.Arai, K.Yoshida and M.Uotani財団法人　電力中央研究所　　東京都 M.Kambe, M.Arai, K.Yoshida and M.UotaniCentral Research Institute of Electric Power Industry Tokyo, Japan  Thermoelectric (TE) power conversion system has been focused as a candidate of direct energy conversion systems from nuclear energy source to meet the various power requirements in next century. In order to achieve high thermal energy density in TE power conversion systems, conduction coupling of TE cell to both hot and cold exchangers is essential. This paper discusses how the challenges of mechanically attaching both ends of the TE cell to hard structure have been addressed. An attempt has been made to adopt FGM compliant pads of C-Pd-Si3N4-C for hot side, and C-Cu-Si3N4-C for cold side. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 633-638 傾斜機能エネルギー変換材料の傾斜電位設計 GRADIENT POTENTIAL DESIGN FOR FUNCTIONALLY GRADIENT ENERGY CONVERSION MATERIALS 平野徹　L.W. Whitlow　寺木潤一 　宮島雅史ダイキン工業株式会社　MEC 研究所　　つくば市 T. Hirano, L.W. Whitlow, J. Teraki and M. MiyajimaMEC Laboratory, Daikin Industries, Ltd., Tsukuba, Japan  In order to improve the conversion efficiency of energy conversion materials, precise estimation of transport properties and tailoring of microstructure are required. For the estimation of transport properties, different scales of physical structures, ranging from lattice level crystal structure to grain level microstructure, are considered. Several estimation methods of the material properties for the design of Functionally Gradient Energy Conversion Materials are presented.   As one of the energy conversion materials, thermoelectric (TE) material is investigated. A model is presented for the transport properties of heavily doped TE semiconductors. Electron and phonon transport coefficients are calculated using band theory. Then, possibility of gradient potential design is presented based upon parametric study of temperature dependence in the transport properties of TE semiconductors. A theoretical framework for estimating the effects of superlattice application to TE material is also described. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 639-643 チョォクラスキー法で作製したBi2Te2.85Se0.15 単結晶キャリア傾斜電熱材料 CARRIER GRADIENT THERMOELECTRIC MATERIAL OF Bi2Te2.85Se0.15 SINGLE CRYSTAL FABRICATED WITH CZOCHRALSKI TECHNIQUE 海部宏昌 1, 奥村次徳 1, M.A.Okamoto 2 and 西田勲夫 21 東京都立大学　　東京都八王子市2 金属材料技術研究所　 　茨城県つくば市 H.T.Kaibe 1, T.Okumura 1, M.A.Okamoto 2 and I.A.Nishida 21 Tokyo Metropolitan University, Hachioji-shi, Tokyo 2 National Research Institute for Metals, Tsukuba-shi, Ibaraki, Japan  The carrier concentration and conduction type of Bi2Te2.85Se0.15 grown by the Czochralski technique were continuously changed along the growth direction due to the change in the composition of Se and Te whose vapor pressure are comparatively high. A pi-shaped thermocouple was made with p- and n-type legs which were cut from separate boules, and Zmax of the thermocouple was as high as 2.4 x10-3 K-1 at 245 K. The results indicate that the continuous and artificial change in Zmax and the optimum temperature Topt can be made by carrier gradient. Such an improvement attains to the highest efficiency of those made of materials with uniform carrier concentration and is powerful for applications of wide temperature ranges. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 645-649 溶融炉組成の電気的絶縁体のためのFGM作製 FABRICATION OF FGM FOR THE ELECTRIC INSULATION OF FUSION REACTOR COMPONENTS 川村昌志 1　松崎祐司 1　藤岡順三 1　山崎誠一郎 2　西尾敏 3　多田栄介 3 　阿部哲也 31 川崎重工業株式会社　明石技術研究所2 川崎重工業株式会社　原子力本部　3 日本原子力研究所 M.Kawamura, Y.Matsuzaki 1, J.Fujioka 1, S.Yamazaki 2, S.Nishio 3, E.Tada 3 and T.Abe 31 Akashi Technical Institute, Kawasaki Heavy Ind. Ltd. 2 Nuclear Systems Division, Kawasaki Heavy Ind. Ltd. 3 Japan Atomic Energy Research Institute  Electric insulation of the components in a tokamak fusion experimental reactor is required to prevent damage by the electromagnetic force due to the induced current generated by plasma disruption. For the purpose of reducing the induced current, a stainless steel / PSZ-Al2O3 / stainless steel functionally gradient material (FGM) with its composition graded in the axial direction has been developed. This FGM joint is expected to be more reliable than the conventional ceramic brazing joint as an electric circuit break because it has less residual stress and higher leak tightness. When the FGM joint is manufactured using the powder metallurgical method, residual thermal stress generated in the sintering process is a critical issue. Thermal stress analysis indicated that the thermal expansion coefficient of the FGM's constituent elements and the graded layer thickness are key parameters in reducing residual thermal stress. In this paper, the successful fabrication of a tubular FGM joint as an electric insulation components is described. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 651-656 固体酸化燃料電池のための、傾斜機能電極と電解質 FUNCTIONAL GRADIENT ELECTRODE/ELECTROLYTE FOR SOLID OXIDE FUEL CELLS: Gradient materials design for an electrochemical energy conversion device K. Sasaki and L.J. GaucklerSwiss Federal Institute of Technology Nichtmetallische Werkstoffe Zurich, Switzerland K. Sasaki and L.J. GaucklerSwiss Federal Institute of Technology Nichtmetallische Werkstoffe Zurich, Switzerland  Contrary to the monostructural electrode, structural designs enable us to use different materials, microstructure and functions to improve solid oxide fuel cells. Requirements in each compound are specified, several possible structures with gradient configurations are proposed, and some examples are demonstrated. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 657-661 広い温度範囲での区分傾斜複合材の熱電特性のための測定法 A MEASUREMENT SYSTEM FOR THERMOELECTRIC PROPERTIES OF GRADUALLY-SEGMENTED COMPOSITE ELEMENTS OVER A LARGE TEMPERATURE SPAN 木皿且人　陳立東　須藤孝幸　桜中登　新野正之航空宇宙技術研究所　角田宇宙推進技術研究センター　　宮城県角田市 K.Kisara, L.Chen, T.Sudo, N.Sakuranaka and M.NiinoNational Aerospace Laboratory, Kakuda Research Center, Kakuda, Miyagi, Japan  A large-temperature-difference apparatus has been designed and built for thermoelectric performance evaluation of gradually-segmented composite elements. This apparatus can simultaneously measure Seebeck voltage, electrical resistance, temperature profiles and heat flux through the specimen during the same thermal cycle. Measurement can be made up to 1500 K with a large temperature span up to 800 K. Especially, efforts have been made to control axial heat flow pattern under high heat flux and large temperature span conditions. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 662 高温固体酸化燃料電池における、金属セラミック組成間の界面機能層 INTERFACIAL FUNCTIONAL LAYERS BETWEEN METALLIC AND CERAMIC COMPONENTS IN THE HIGH TEMPERATURE SOLID OXIDE FUEL CELL H. Schmidt 1, M. Schnoller 1, E. Fendler 2 and B. Bruckner 21 Siemens AG, Corporate Research and Development, Munchen2 Siemens AG, Power Generation Group KWU, Erlangen, Germany H. Schmidt 1, M. Schnoller 1, E. Fendler 2 and B. Bruckner 21 Siemens AG, Corporate Research and Development, Munchen2 Siemens AG, Power Generation Group KWU, Erlangen, Germany  In the planar Siemens design of the solid oxide fuel cell a metallic bipolar plate is used to separate the ceramic single cells. These ceramic single cells consist of yttria-stabilized ZrO2 electrolytes, (La,Sr)MnO3 cathodes and Ni-cermet anodes.       During operation at 950deg.C an electrical contact between the metallic plate and the screen printed electrodes has to be maintained. This problem can be solved using intermediate layers between the metallic plate and the single cells. These layers have to be ductile at least before the first heating of the stack. Porous layers will fulfill this requirement; in addition, these functional layers must prevent a CrO3 evaporation from the metallic bipolar plate, because the used metal forms a Cr2O3 scale, which is volatile as CrO3 in an oxygen atmosphere at 950deg.C. The CrO3 condensates in the cathode and leads to a decrease in the long term stability of the SOFC. In contrast to the contacting layer this protective layer has to be dense.       To solve these problems functional layers are being developed. In a first stage of development the two types of layers are being investigated separately due to their required different functions. In the future a gradient material with regard to chemical composition and structure will be favorable.       At present different compositions in the system (La,Sr)(Mn,Co)O3 are investigated as contacting layers. The materials are characterized by X-ray diffraction, thermal expansion coefficient measurements and electrical conductivity measurements. As protective layers, doped LaCrO3 and doped YCrO3 have been studied. Several different deposition techniques are applied. The effectiveness of the protective layers is tested by diffusion experiments and cell measurements. The interface reactions will be studied by scanning electron microscopy and transmission electron microscopy. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 667-671 アルミニウム とポリイミドによる傾斜機能材料 FUNCTIONALLY GRADIENT MATERIALS FROM Al AND POLYIMIDE 大森守、酒井広隆、大久保昭、平井敏雄東北大学　金属材料研究所　　宮城県仙台市 M.Omori, H.Sakai, A.Okubo and T.HiraiInstitute for Materials Research, Tohoku University, Sendai, Japan  Functionally gradient materials (FGM) of a metal/polymer combination have been prepared from Al and polyimide powders using a spark plasma sintering apparatus. This apparatus is a sort of a hot press without a heating element. The graphite die is heated by a direct pulse current. The die, designed with the upper and lower parts having different diameter, creates a graded temperature according to a variable resistivity. Al was sintered at ca. 410deg.C, and polyimide was solidified at 325deg.C. Interposed layers of a mixture of two materials were heat-treated at 325deg.C-410deg.C. The metal/polyimide FGM was dense without pores and cracks. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 673-678 上昇温度での異なる硬化積層複合材固定列の破壊機構への効果 EFFECT OF STAKING SEQUENCE OF LAMINATED COMPOSITE WITH DIFFERENT CURE ON THE FRACTURE MECHANICS AT ELEVATED TEMPERATURE E.I.Elghandour 1, F.A.Kolkailah 1, S.A. Khalil 2 and S.R.Naga 21Aeronautical Engineering Department, California Polytechnic, San Luis Obispo, California, U.S.A. 2 Department of Mechanical Design, College of Engineering and Technology, Mataria, Cairo, Egypt E.I.Elghandour 1, F.A.Kolkailah 1, S.A. Khalil 2 and S.R.Naga 21Aeronautical Engineering Department, California Polytechnic, San Luis Obispo, California, U.S.A. 2 Department of Mechanical Design, College of Engineering and Technology, Mataria, Cairo, Egypt  In is study, the effect of the stacking sequence of laminated composite cured at different cycles on the stress intensity factors of a crack in an infinite composite plate is investigated at elevated temperatures. A number of 8-ply from 977-2 fiberite carbon fiber/epoxy resin (lM7) flat plats is fabricated for three different stacking sequence with four different curing cycles. A total of twelve double notched specimens are constructed from the fabricated plates and subjected to a tensile test at elevated temperature ranging between room temperature and 149deg.C in steps of 38deg.C each. A heat test chamber is constructed to heat the test specimens. The elevated temperature is controlled by changing the voltage to the heat coils. Multiple strain gages are used to measure the maximum stress near the crack tip. The output data is employed to determine the stress intensity factors and the toughness of the composite as function of temperature. As to the numerical task of this work, the stress distribution across the loading head near the crack tip is calculated using the finite element analysis for different laminated plates with double edge cracks. The laminated plate theory for orthotropic composite material is employed in this analysis using different the linear elastic fracture mechanics approach. The experimental and numerical results are in very good agreement. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 679-684 傾斜機能分子構造(FGM)を持つスチレン-ブタジエン漸減ブロック共高分子(TBC) STYRENE - BUTADIENE TAPERED BLOCK COPOLYMER (TBC) HAVING A FUNCTIONALLY GRADED MOLECULAR-STRUCTURE (FGM) 浅井新一郎電気化学工業総合研究所　東京都 S.AsaiResearch Center, Denki Kagaku Kogyo K.K., Tokyo, Japan  Anion living polymerization produces a block copolymer when the living end of the polymer takes in different monomers successively. A tapered copolymer can be produced when the living end takes in two different monomers gradually changing the monomer composition. With these two procedures, a TBC can be obtained.       A TBC (polystyrene-b-styrene/butadiene tapered copolymer-b-polystyrene) with 150,000 molecular weight and 70 - 90 wt% styrene was polymerized/molded into a tough transparent resin, while the clear-cut block copolymer with the same styrene content/configuration (polystyrene-b-polybutadiene-b-polystyrene) behaved as a brittle resin. The high impact strength and great energy dissipation of the TBC seem to be due to the interlayer between polystyrene and tapered copolymer domains. The morphology of the TBC was also different from the corresponding clear-cut block copolymer. This TBC resin does not craze like a conventional rubber-modified high impact resin. The TBC is now used not only as a high impact transparent resin, but it has many other applications with its unique characteristics. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 685-688 係数傾斜高分子材料のコンピューター設計、合成そして研究 COMPUTER DESIGN, SYNTHESIS AND INVESTIGATION OF POLYMER MATERIALS WITH A GRADIENT OF MODULUS A.AskadskiiLaboratory of Polymeric Materials, Institute of Organoelement compounds of the Russian Academy of Sciences. Moscow, Russia A.AskadskiiLaboratory of Polymeric Materials, Institute of Organoelement compounds of the Russian Academy of Sciences. Moscow, Russia  Gradient-modulus polymeric materials have been prepared, which show a continuous transition, within the same sample, from rubber to plastic without any junctions, joints, etc. These materials are elastic and have a modulus ranging from 3 to 3000 MPa. The properties of the materials were calculated before their synthesis. It was shown that a prerequisite of such materials is a network structure comprising rigid bulky crosslinked points and flexible linking chains. Another prerequisite of such materials is the occurrence of microphase separation. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 689-694 竹の階層傾斜構造 HIERARCHICAL GRADIENT STRUCTURES OF BAMBOO 天田重庚、宗像保、Y. Nagase、清水尚之群馬大学　工学部　　群馬県 S.Amada, T.Munekata, Y.Nagase and N.ShimizuSchool of Engineering, Gunma University Gunma, Japan  For a long period bamboos have acquired their structures which fit into the natural and external environments. They are a composite material reinforced axially by fibers called bundle sheath. Furthermore, they have a hierarchical structure, that is, a macroscopic gradient structure in culm diameter, thickness and nodal length, and a microscopic one in the bundle sheath distribution. These structures play different roles against the environmental loads. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 695-701 木材の多段階傾斜構造 WOOD MULTILEVEL GRADIENT STRUCTURE N.ParvizMaterials Department, Laboratory of Building Materials Swiss Federal Institute of Technology of Lausanne, Switzerland N.ParvizMaterials Department, Laboratory of Building Materials Swiss Federal Institute of Technology of Lausanne, Switzerland  Nature produces every year over one billion tons of wood mostly with a gradient structure in its different microscopical levels. The annual increment (growth ring) consists of early wood and late wood composed of wood cells. In softwoods the early wood cells have a large-section area, a thin wall and a big cavity called lumen. The late wood cell has small cross-section, thicker cell wall and smaller lumen. In most softwoods there is a gradual transition from large porosity in early wood to smaller porosity in late wood so that the wood apparent density increases gradually from early to late wood. A transversal view of a softwood stem shows that in general the thickness of growth rings diminishes from centre to the bark. Hard woods, on the other hand are characterized by their vessels, or pores, are classified as ring-porous or diffuse-porous woods, depending on the pore arrangement within the growth ring. Hard wood such as Chestnut, English Ash, Oak and Locust present ring pores with gradual transition from large pores of early wood to small pores of late wood. These woods with their gradient structures are well known to have durability under severe climatic conditions with or without a contact with soil. This paper intends to demonstrate, first, the gradient structure of wood in its different micro- and macro-level and then to establish the relation between wood cell rigidity and its gradient structure. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 703-708 チタンとヒドロキシアパタイト組成の傾斜機能歯科インプラント FUNCTIONALLY GRADED DENTAL IMPLANT COMPOSED OF TITANIUM AND HYDROXYAPATITE 亘理文夫 1,横山敦郎 2, 佐相史徳 2, 宇尾基弘 1 ,川崎貴生 11 北海道大学　歯学部2 北海道大学　歯学部科理工学講座　　北海道札幌市 F.Watari 1,A.Yokoyama 2, F.Saso 2, M.Uo 1 and T.Kawasaki 11 Department of Dental Materials and Engineering2 Department of Removable Prosthodontics, School of Dentistry, Hokkaido University, Sapporo, JAPAN  Functionally graded dental implants composed of the metal titanium and hydroxyapatite (HAP) have been prepared. HAP, which exhibits excellent biocompatibility with bone, is brittle and easily results in fracture during practical use. Ti, one of the best biocompatible metals, can maintain the mechanical toughness. The implant was designed to provide more Ti for the upper part where the occlusal force is directly imposed and more HAP for the lower part which is buried inside the jawbone. Mixed powders with different compositions packed in the silicon rubber molds were compressed at 400 MPa by CIP. The compact was sintered in argon gas by high frequency induction heating at 1300deg.C. Compressive and flexural tests have been performed. The average flexural strength of the FGM specimens was 150 MPa which is approximately comparable to the strength of human bone. The surface and cross-section observed by optical and electron microscopy showed the distribution of porosity and HAP in the Ti matrix. The gradual change of concentration was confirmed by the analysis of elemental distribution using EPMA. An implant test into the femora of rats was done in order to estimate the biocompatibility. Newly formed bone was partially in contact with the implant in the case of Ti, whereas in the Ti/HAP FGM new bone was in contact with the major part of the implant. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 709 アメリカ合衆国における傾斜材料についての最近の調査 CURRENT RESEARCH ON GRADED MATERIALS IN THE USA S.SureshMassachusetts Institute of Technology, Cambridge MA, USA S.SureshMassachusetts Institute of Technology, Cambridge MA, USA  An International Workshop on "Functionally Graded Structural Materials" was held at the Massachusetts Institute of Technology, Cambridge, MA, on March 28 and 29, 1994, under the sponsorship of the Materials Processing Center at MIT and the Office of Naval Research. This workshop brought together dozens of US researchers and leading overseas researchers, mainly from Japan and Europe, representing academia, industry and government.       Although there is no centralized national program on Functionally Graded Materials, as there has been in Japan for a number of years, there is a rapidly expanding interest in the science and technology of graded materials for a wide variety of structural and non-structural applications. Such interest encompasses application areas as broad as thermal barrier coatings for propulsion systems, wear resistant coatings for ground vehicle components, structural components for space vehicles, solid oxide fuel cells, biological systems, energy conversion devices, layered components for microelectronic devices, etc. All the processing techniques discussed at this meeting are being studied. Centers where focussed research activities are currently in progress in the US include (but are not limited to) Alfred University, Caterpillar Corporation, Colorado School of Mines, Johns Hopkins University, Idaho National. Engineering Laboratory, Lawrence Livermore National Laboratory, Lehigh University, Los Alamos National Laboratory, Massachusetts Institute of Technology, National Institutes of Standard and Technology, State University of New York at Stony Brook, United Technologies Research Center, University of California at Berkeley, and Westinghouse R&D Center. English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 710 ドイツにおける傾斜機能材料についての国家研究プログラム A NATIONAL RESEARCH PROGRAM ON FUNCTIONALLY GRADED MATERIALS IN GERMANY J. Rodel*Darmstadt University, Germany J. Rodel*Darmstadt University, Germany  First advances to initiated the German scientific core program on "Gradient Materials" date back to Spring 92, when first alliances among the already existing small German FGM community were formed. In the meantime, DFG (the Deutsche Forschungsgemeinschaft) has agreed to fund a 6-year program on Gradient Materials. The program promises to be a diverse one with a strong fundamental core. Modelling, processing and properties/characterization are to be the main themes of the program with no limitation on particular applications in mind, but initiated to promote a fundamental understanding of the influence of gradients in either chemistry, microstructure or atomic ordering on material properties. Special physical or thermomechanical properties and especially combinations of these properties are therefore included. Strong collaboration between various laboratories is strongly encouraged. The gradients are to form a large share of the active part of a particular component.       While the help of the programming committee and especially help by the first German supporters of FGM (Profs. Bunk, Kaysser and Munz) as well as others is gratefully acknowledged in initiating this program, we now turn to seek help in the German broader scientific community for reviewing the scientific applications. In the sense of the international spirit of FGM, it is therefore particularly appropriate and of tremendous help, that Prof. Ilschner as head of the Swiss Materials Program and leading European scientist could be gained as the head of the reviewing committee of the German program.       The German FGM community feels therefore well positioned to enlarge its scientific contributions to the international work on gradient materials and is already looking forward to the next conference to be held in Japan.  English 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 3rd Internattional Symposium on Structural and Functional Gradient MaterialsFGM'94PROCEEDINGS 8 1994-12-31 711 結びのことばと、1996年、日本におけるFGM' 4への招待 CONCLUDING REMARKS AND INVITATION TO FGM' 4 IN JAPAN, 1996 小泉光恵*龍谷大学 M. Koizumi*Ryukoku University, Seta, Japan  At the 3rd International Symposium on FGM held in the beautiful city of Lausanne, Switzerland, October 10-12,1994, about 200 scientists from 22 countries, came together and 125 papers were presented. We could learn the present status of R&D on FGM in the world, discuss various problems and exchange acquaitanceship. On behalf of international FGM community, I would like to express our sincere thanks to Professor B.Ilschner and Dr. N. Cherradi, who mainly organized this symposium and lead it to great success. A reception at the Olympic museum and a banquet at Chillon castle belong our fantastic memories as well.       The number of presented papers increased over two times compared to those of the former two symposiums. It should also be noted that the topics of FGM are extending to energy conversion materials, polymers and biomaterials, besides high heat, wear and/or corrosion resistant materials. These trends suggest that the FGM concept is being established in many materials areas all over the world.       The International Advisory Committee of FGM (IACFGM) was established in 1990 to promote international cooperation on R&D in the field of FGM and to arrange international symposiums and workshops.       IACFGM is a center for the scientific and industrial community of FGM, which consists of twenty representatives of ten countries at present.   IACFGM meeting in Lausanne decided that the next symposium will be held in 1996 in Japan. We, the Japan community of FGM, feel highly honored and pleased to welcome the international FGM community. Further investigations and many new directions of FGM are expected to emerge by the 4th symposium. English