# Fileset [proc-fgm-1994.xlsx](https://mdr.nims.go.jp/filesets/37529cb8-d993-4d38-aa0f-797b9d3f113b/download) ## Creator National Institute for Materials Science ## Rights ## Other metadata [FY 1994 Proceedings of Functionally Gradient Materials (FGM'94) ](https://mdr.nims.go.jp/datasets/be50baff-ba88-4e17-8f6e-f35e8adc0bda) ## Fulltext Sheet1 BookTitle_j BookTitle_e Volume/Issue Issueddate Page Title_j Title_e AuthorList_j AuthorList_e Abstract Language １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 1-8 遮熱型傾斜機能材料の耐熱衝撃損傷設計 Thermal Shock-Resistant Design of Heat Insulation Typed Functionally Gradient Material 松崎祐司、川村昌志、藤岡順三、岡崎章三川崎重工業株式会社 明石技術研究所 Yuji Matsuzaki, Masashi Kawamura, Junzo Fujioka, Shozo OkazakiAkashi Technical Institute, Kawasaki Heavy Industries, Ltd. An application-capable damage mode modeling is needed for the FGM to realize the full potential of the thermal barrier performance and the durability benefits in practical service environments. The work reported herein describes the results of experimental and numerical considerations on the thermomechanical response of the FGM in transient thermal cycle environment. The maximum thermal shock resistant temperature of the stabilized zirconia / nickel-chrome FGM was significantly dependent on the compositional distribution. Spallation was observed in very early periods after initiate heating when exposed in high heat flux. Photomicro-graphic evidences indicated that the spallation is caused by the in-plain microcracks, which eventually link-up with vertical cracks associated with the inelasticity of the zirconia ceramics. FEM analysis revealed both type of these cracks to be initiated as a result of large in-plain compressive stress during the heat loaded cycle. Ceramics with adequate coefficient of thermal expansion are estimated to reduce the in-plain stress, improving the heat resistance limit of the FGM. Further thermal cycle test was conducted on stabilized zirconia - 30vol% cordierite / nickel-chrome FGM to illustrate the effect of controlling the high temperature side material thermal expansion on the in-plain stress reduction. The optimized FGM showed 120K higher heat resistant temperature than that of the stabilized zirconia based FGM. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 9-14 セラミックスー金属系傾斜機能材料の熱弾性設計一大局的応力緩和の方法一 Thermoelastic Design for Ceramic-Metal Functionally Graded Material-Scheme to Global Reduction of Thermal Stresses- 渡辺宏一1),　筏尚武1),　○田中喜久昭1),　菅野良弘2〕1)東京都立科学技術大学 航空宇宙システム工学科　東京都日野市旭が丘2)岩手大学　工学部　岩手県盛岡市上田4-3-5 Hirokazu WATANABE1), Hisatake IKADA1), Kikuaki TANAKA1), Yoshihiro SUGANO2)1) Department of Aerospace Engineering, Tokyo Metropolitan Institute of Technology Asahigaoka 6-6, J-191 Hino/Tokyo, Japan 2) Department of Mechanical Engineering, Iwate University Ueda 4-3-5, J-020-02 Morioka/Iwate, Japan Thermoelastic material design in the functionally gradient materials (FGMs) is formulated to reduce globaly the thermal stresses induced in the materials. The direct sensitivity and optimization methods are applied to the incremental thermoelastic/heat conduction finite element analysis. A full spatial distribution in volume fraction of phases and the non-linear dependence of the material parameters on the volume fraction are employed. Numerical illustration of the theory is given for the material design in a hollow circular cylinder subjected to an asymmetric heating on the inner boundary. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 15-18 ガスバーナー試験による傾斜被膜の特性評価 Barner Heating Test of FGM Prepared by Low Pressure Plasma Spray ○下田信之1)、北口三郎1)、向田行宏2)、川崎亮2)、渡辺龍三2)1)新日本製鉄株式会社　技術開発本部　鉄鋼研究所　接合研究センター2)東北大学工学部材料加工学科 N.Shimoda 1) , S.Kitaguchi 1) , I.Mukaida 2) , A.Kawasaki 2) , R.Watanabe 2)1) Welding & Joining Research Center, Nippon Steel Corporation 2) Fuculity of Engineering, Tohoku University For the better understanding of the diffences between the thermal properties of FGM and Non-FGM, the fracture process of FGM in the temperature field, burner heating test was carried out. Low Pressure Plasma Sprayed (LPPS) FGM and Non-FGM, consisting of zirconia and Ni-alloy were prepared for this test. Vertical and complex cruck were showed in ceramics layer. But FGM showed better thermal resistance than Non-FGM in case that the surface temperatures were over 1400K. In both FGM and Non-FGM air cooling specimens, horizontal cracks were appeared. As the results of AE, in the water cooling specimen almost crack were appeared at stop-heating. In the air cooling specimen the cracks were appeared at both on-heating and stop-heating. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 19-22 PSZ-Ni傾斜材の成長する内部欠陥の超音波映像観察 Observation of growing internal defect in Functionally Gradient PSZ-Ni by means of Ultrasonic imaging ○阿部利彦,鷲見新一東北工業技術研究所 Toshihiko Abe, Shin-ichi SumiTohoku National Industrial Research Institute Functionally gradient PSZ-Ni specimens with 6 layer were made by a plasma activated sintering method by which a high density product can be sintered within a short time as compared with a conventional hot press method. The total thickness of the specimens were (1) 7.99mm, (2)4.65mm and (3) 2.77mm. An individual bonded interface and layer were observed by an ultrasonic image which showed mostly no defect in specimen (3), however, slight defects, probably micro cracks, were recognized in specimens (1) and (2). During the observation of the specimen (1) by the image for more than one month, the defects largely expanded after 13 days, then grew to crack image after 37 days. This crack can be seen by eye at the depth and location indicated by the ultrasonic image. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 23-28 衝撃荷重を受ける傾斜機能材料の非線形破壊解析 Nonlinear Fracture Mechanics Analysis of Functionally Gradient Material under Dynamic Shock Load ○中垣通彦、往々木裕幸、萩原世也九州工業大学　情報工学部　820　福岡県飯塚市大字川津 M. Nakagaki, H. Sasaki, and S. HagiharaSchool of Information Science and Systems Engineering Kyushu Institute of Technology, lizuka, Fukuoka-ken 820 JAPAN A numerical modeling and assessment methodology are shown for evaluating fracture severity and stability of a ceramic-metal type functionally gradient material. The material composed of ZrO2 and Ti-6Al-V having a single edge notch is subjected to a remote tensile load of a step function of time. A spherical grain model was used to describe the macroscopic elastic law for the media, in which the defects of microcrack damage are accounted for in the ceramic phase. The solved dynamic average stresses were distributed into those in each phase of the composing materials. The severity of the crack-tip is assessed with the use of the most appropriate fracture parameter T* designated for highly inhomogeneous materials such as the present. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 29-34 Cu-Mo系傾斜機能材料の物理的性質の評価 Evaluation of Physical Properties on Metal Matrix FGM of Cu - Mo ○中野光一1〕,西田新一21)（株）高田工業所　806　福岡県北九州市2)佐賀大学　理工学部　840　佐賀県佐賀市本庄町 K. Nakano 1) ,S. Nishida 2)1) TAKADA Corp., Kitakyushu-City, Fukuoka Pref. 806, Japan 2) Saga Univ., Honjyo-machi, Saga-city, Saga Pref.840, Japan Metal matrix composites (MMC) have been made an attempt to produce by a lot of production processes such as powder metallurgical method, plasma spraying, diffusion bonding, physical vapor deposition, hot isostatic pressing etc. In almost cases of these processes, dissimilar materials are combined or bonded directly. The discontinuity of various kinds of physical properties occurs at the bond interface of dissimilar materials. In order to correct the defect, functionally gradient materials (FGM) attract our notice recently. Because their compositions are prepared so that physical properties will continuously change through the bond interface of dissimilar metals. In this study, a FGM has been produced by a new process based on HIP. Copper and molybdenum, which show much difference of thermo-physical properties, are used. This composition have been confirmed by characteristics X-ray images of each mixed layer for FGM. In addition, Vickers hardness, thermal expansion, and thermal conductivity are also investigated. Good agreements have been shown between those measured values and linear law of mixture rule. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 35-40 Cu-Mo系傾斜機能材料の静的および動的な機械的性質の評価 Evaluation of Mechanical Properties on Metal Matrix FGM of Cu-Mo ○中野光一1),　西田新一2),　服部信祐2〕1)（株）高田工業所　806　福岡県北九州市　2)佐賀大学　理工学部　840　佐賀県佐賀市本庄町 K. Nakano 1), S. Nishida 2), N.Hattori 2)1)TAKADA Corp., Kitakyushu-City, Fukuoka Pref. 806, Japan 2) Saga Univ., Honjyo-machi, Saga-city, Saga Pref.840, Japan Powders of copper and molybdenum, which show much difference of thermo-physical properties, are used in this study. Samples with compositional gradient and uniform mixed samples have been produced by HIP method. Macro and micro scopic observation using a optical microscope and a scanning electron microscope (SEM) are carried out to investigate the compositional gradient about these samples. Hardness tests, tensile tests, and rotating bending fatigue tests are performed to investigate the functional gradient about these samples. The following items have been investigated and compared with the linear low of mixture rule : Vickers hardness, tensile strength, Young's modulus, elongation, fatigue limit based on fatigue strength at 10**7 cycles. Fracture surfaces after tensile tests and rotating bending fatigue tests are observed by SEM. Growth process of micro-crack on the notched surface of the test specimen have been observed continuously by replica method. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 41-46 SiC/C傾斜組成黒鉛材料の曲げおよび圧縮試験 Bending and compressive tests of SiC/C compositionally gradient graphite materials ○中野純一1)、藤井貴美夫1)、山田禮司1)、勝田博司1)1)日本原子力研究所　材料研究部　319-11　茨城県那珂郡東海村 J.Nakano l), K.Fujii l), R.Yamada l) and H.Katsuta l)1) Japan Atomic Energy Research Instuitute, Tokai-mura, Ibaraki-ken 319-11, Japan For the developed compositionally gradient graphite materials, which are composed of a surface SiC coating layer, a compositionally gradient SiC/C layer and a graphite matrix, bending and compressive tests were carried out together with surface SiC coated graphites, graphites only with the compositionally gradient SiC/C layer, and virgin graphites at room temperature in air. The results of the tests were discussed in terms of the specific surface areas which are a measure for the surface conditions of samples. For the graphite only with the SiC/C layer, the bending and compressive strengths were independent of the Si content in the SiC/C layer and almost the same as those for the virgin graphites although the specific surface area increased with an increase in the Si content in the SiC/C layer. The bending strength of specimens with the surface SiC coating layer, i.e., SiC/C compositionally gradient graphite materials and SiC coated graphite materials, was about twice as that of the specimens without SiC coating layer. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 47-52 Al-Al3NiFGM厚肉円筒管における残留応力評価 Macroscopic Residual Stress Evaluation of Functionally Graded Al-Al3Ni Material Thick-Walled Tube by a Cutting Method 福井泰好1)、上谷俊平1)、中西賢二1)1)鹿児島大学　890　鹿児島県鹿児島市郡元 Y.Fukui l), S.Kamitani l) and K.Nakanishi l)1) Kagoshima University, Korimoto, Kagoshima 890, Japan Macroscopic residual stress of the thick-walled tubes of an in-situ Al-Al3Ni functionally graded material (FGM) has been studied based on a cutting method. The tubes that were fabricated by a centrifugal method have two kind of graded volume fraction of Al3Ni intermetallic particles in a continuous Al phase. They are G=147 and G=23 having variation of the Al3Ni phase fraction from 0.03 at inner plane to 0.59 at outer plane and from 0.24 to 0.55, respectively. The level of macroscopic residual stress present in the hoop direction can be modelled accurately using an uniform temperature change of 160K from an assumed stress free temperature of half the melting point. The residual stress distribution changes through-thickness from tension at inner surface to compression at outer surface. The residual stress of the G=147 and G=23 tubes are found to vary from 37 to -19MPa and from 20 to -14MPa, respectively, across the tube-wall thickness from the inner to outer surface. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 53-58 熱電発電器のモジュール接触部の熱応力緩和の実現条件 Preliminary evaluation of requirement to lighten the thermal stress in a thermoelectric module of a thermoelectric generator 津吉　彰1)　松浦虔士2)1)神戸市立工業高等専門学校　2)大阪大学 A.Tsuyoshi l) K.Matsuura 2)1) Kobe City College of Technology 2) Osaka University Thermal resistance on the contact between a thermoelectric module and a heat transfer tube was investigated. Then it was proved that contact thermal resistance should not be negligible. Additionally some problems concerning to thermal stress in a thermoelectric module was presumed when it was used in high temperature. So the unit which a heat transfer tube, electric insulators and electrodes were combined as functionally gradient material was proposed and investigated. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 59-64 MoSi2/Al2O3/Ni/Al2O3/MoSi2対称型傾斜機能材料における強化と拡散防止 Reinforcement and Diffusion Control in the MoSi2/Al2O3/Ni/Al2O3/MoSi2 Symmetric FGMs. 康燕生1)、宮本欽生1)、村岡芳幸2)、山口修2)1)大阪大学　産業科学研究所、2)同志社大学　工学部 Yan-Sheng Kang1),Yoshinari Miyamoto1),Yoshiyuki Muraoka2) and Osamu Yamaguchi2)1)ISIR, Osaka University. 2)Faculty of Engineering, Doshisha University. Symmetrically graded materials of the MoSi2/Al2O3/Ni/Al2O3/MoSi2 systems were fabricated by SHS/HIP compaction. Owing to the different thermal expansion rate of the inner Al2O3-Ni layer and the outer MoSi2, a compressive residual stress (up to 100 MPa) was induced in the MoSi2 surface. The fracture toughness reached 5.8 MPa*m1/2 which is 50% higher than the monolithic MoSi2. The hardness on the MoSi2 was 11 GPa and the flexural strength of FGMs was 580 MPa. The Al2O3 phase incorporated acted as a diffusion stopper to Ni at 900deg.C. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 65-68 Al2O3/TiC/Ni/TiC/Al2O3系対称型傾斜機能材料の強化機構 Mechanism of Compressive Reinforcement in the Symmetric Functionally Graded Materials of the Al2O3/TiC/Ni/TiC/Al2O3 System ○栗振思,谷畑公昭,宮本欽生大阪大学　産業科学研究所 ○Zhensi Li, Kimiaki Tanihata, Yosinari MiyamotoInstitute of Scientific and Industrial Research, Osaka University Mechanism of the compressive reinforcement was analyzed for the Al2O3/TiC/Ni/TiC/Al2O3 system with symmetric graded structures which were prepared by SHS/HIP. Strong compressive residual stress as much as 180~240 MPa was produced in the outer Al2O3 layer due to the difference of thermal expansion between the inner and outer layers. This stress acted to reinforced the surface Al2O3 layer and caused to exhibit flow tolerance, that is R-curve behavior. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 69-74 ステンレス/ジルコニア系両側傾斜機能材料の焼結バランス制御 Sintering Behavior Control of Stainless Steel / PSZ Functionally Graded Material ○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)、阿部哲也3）、多田栄介3）1)川崎重工業(株)明石技術研究所　673　兵庫県明石市川崎町2)川崎重工業(株)原子力本部　136　東京都江東区南砂3)日本原子力研究所　311 -02　茨城県那珂郡那珂町大字向山 M.Kawamura 1), Y.Matsuzaki1), J.Fujioka 1), S.Yamazaki2) S.Nishio 3), E.Tada 3), T.Abe 3)l)Akashi Technical Institute, Kawasaki Heavy Ind.Ltd., Kawasaki-cho. Akashi. Hyogo 673, JAPAN 2)Nuclear System Division, Kawasaki Heavy Ind.Ltd., Minamisuna, Koto-ku, Tokyo 136, JAPAN 3)Japan Atomic Energy Reserach Institute, Mukoyama, Naka-machi, Naka-gun, Ibaraki 311 -02, JAPAN 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, deformation due to difference in sintering behaviors between ceramic and metal is happen and sometimes causing cracks. This deformation is caused by a lower initial packing density for the ceramic part than the metallic part. Therefore, the grain size distribution of the ceramic raw material powder was adjusted by mixing larger ceramic particles into the ceramics with the aim of achieving uniform packing density throughout the FGM green compact. It was revealed that the sintering shrinkage of ceramic, metal and its homogeneous composites were almost same when ceramic powder of 40% large particle content was used. Using this improved ceramic powder, FGM joint was successfully fabricated by HIP sintering method. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 75-80 大出力ハイブリッドプラズマ溶射法の開発 Development of high power hybrid plasma spraying 浜谷秀樹、北口三郎、小原昌弘新日本製鉄(株)　鉄鋼研究所接合研究センター H.Hamatani, S.Kitaguchi, H.OharaNippon Steel Corporation A hybrid plasma spraying device with a power as high as 300kW was developed. This furnished approximate 14% as a energetic efficiency that is heat transfer to plasma gas against a power input. Plasma was defined in this study to be stable neither when plasma arc extinguishes nor when cracking of an inner tube of a plasma torch occurs. The stability of plasma was strongly influenced by the power supplied nitrogen and hydrogen mixture gas. The maximum power input was limited 350kW because of cracking of plasma torch with the inner diameter of 70mm. Plasma spraying of Cobalt based alloy powder was carried out by this device. In case of including unmelted powder, the strength of coating decreased with increasing of powder size. On the other hand, in case of excluding unmelted powder, the strength increased with increasing of powder size. Satisfactory dense coatings without cracks and porosity were formed, and under the optimum condition, the strength of coating was about 1350MPa and the interface strength was up to 270MPa. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 81-86 温度差熱処理による鋳造材料の傾斜機能化 Development of Functionally Gradient Cast Material by means of Temperature Difference Heat Treatment 多田周二1）、高橋利夫1〕、阿部利彦1〕1）東北工業技術研究所　983　宮城県 S.TADA 1) , T.TAKAHASHI 1) , T.ABE 1)1) Tohoku National Industrial Research Institute, Miyagi Pref. 983, JAPAN We have developed functionally gradient cast material by means of temperature difference heat treatment. Although the austempering of spheroidal graphite dutile cast iron is able to produce ADI (Austempered Ductile iron) with excellent mechanical properties, this treatment enables improvement only in tensile strength or toughness, and enhances one to the detriment of the other. Now, however, by means of an imposed temperature difference, austempering results in the production of a new type of ADI, known as FGADI, which possesses functionally gradient mechanical properties. As a result of temperature difference austempering, the mechanical properties of FGADI vary along the direction corresponding to the temperature gradient. Because of this mechanical property gradient, FGADI shows an interesting bending behaviour whose fatigue life depends strongly on the loading direction. Also, it is clear that the compressive property in a ring specimen must be improved by applying a negative temperature gradient in its radial direction. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 87-92 次世代耐熱複合材料としてのC/Cコンポジットと傾斜機能コーティング Carbon-Carbon Composites and FGM Coatings for future High-Temperature Materials 早田喜穂、久手幸徳、木内規之、井土泰二日本石油株式会社中央技術研究所　231　横浜市 Y. Sohda, Y. Kude, N. Kiuchi and Y. IdoNippon Oil Company, Ltd. Yokohama 231, Japan Carbon-carbon (C-C) composites using petroleum pitch based carbon fibers have been studied for future applications. Autoclave curing with UD phenol prepreg or a pitch binder hot press with spread woven fabric was used as the shaping method. Petroleum pitch matrices were superior to all other matrices in terms of high carbon yield, oxidation resistance and ease of graphitization. The HIP carbonization process made it easy to density C-C composites. The thermal expansion behavior of C-C composites, which was governed by their graphitization temperature, was recognized as a key factor in the formation of coatings with good oxidation resistance. The higher the heat treatment temperature was, the more difficult the coating was. The effectiveness of the SiC-C FGM coating upon both the oxidation resistance and the strength maintenance was shown in comparison with the conventional coated C-C composites. In order to avoid coating delamination, hybrid C-C composites, which were comprised of both plain fabric for the surface structures and UD laminates for the internal structures as reinforcements, were proposed. On the basis of this fundamental research, new manufacturing processes have been established which produce 2D-C-C composites with the tensile strength of 712 MPa at 2000deg.C in vacuum and 625 MPa at 1600deg.C in air. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 93-98 Si3N4-MO系傾斜機能材料の作製と評価 Fabrication and Evaluation of Si3N4-Mo FGMs ○熊川彰長1)、高橋守1)、佐々木正樹1)、新野正之1)、渡辺龍三2)、S.W.Huelsman3)、W.Bunk3)1)航空宇宙技術研究所　角田研究センター　宮城県角田市2)東北大学　宮城県仙台市3)Institute for Material Research, DLR, Koln, Germany A. Kumakawa 1), M. Takahashi 1), M. Sasaki 1), R. Watanabe 2), S. W. Huelsman 3) and W. Bunk 3)1) Kakuda Research Center, NAL, Kakuda, Miyagi, Japan 2) Tohoku Univ., Sendai Miyagi, Japan 3) Institute for Material Research, DLR, Koln, Germany Si3N4-Mo FGMs were successfully fabricated by using a hot pressing process at DLR. After mixing two kinds of powder, Si3N4 and Mo, in desired compositions, six layers were stacked according to the designed constitution gradient. They were hot-pressed in a carbon resistive furnace. Then two FGM specimens with a diameter of 30 mm were tested under large-temperature-difference conditions at NAL. One FGM specimen, which was tested under lower bottom-side temperature, was almost sound after 16 cycles of thermal exposure. The other specimen, which was tested under higher bottom-side temperature, was damaged and the effective thermal conductivity decreased steeply. Its effective thermal conductivity was almost coincided with ones that were calculated by the modified Einsten equation which was previously proposed based on the result of a ceramics coated thrust chamber. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 99-104 金属(Ni,SUS316)/ZrO2(3Y)傾斜機能材料の合成 Fabrication of Metals(Ni,SUS316)/ZrO2(3Y)FGM 大森守1)、酒井広隆1)、大久保昭1)、鴇田正雄2)、川原正和2)、平井敏雄2)1)東北大学　金属材料研究所　　980-77　仙台市2)住友石炭鉱業(株)　213　川崎市高津区 M.Omori1),H.Sakai1),A.Okubo1),M.Tokita 2),M.Kawahara 2) and T.Hirai1)1)institute for Materials Research,Tohoku University,Sendai 980-77,Japan2)Sumitomo Coal Mining Co.Ltd.,Takatsu-ku,Kawasaki 213,Japan FGMs were fabricated from metals (Ni and SUS316) and ZrO2(3Y). Residual stress due to thermal expansion mismatch was relaxed by the plastic deformation of metals. The large grain in FGM increased the residual stress to crack it. The distribution of the residual stress changed according to the distribution of compositions. Concentration of stress on a ZrO2(3Y) layer resulted in cracking it. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 105-110 AlN/W系超耐熱傾斜機能材料の熱衝撃特性 Thermal Shock Behavior of AlN/W Super Thermal Barrier Functionally Gradient Material ○向田行宏、川崎亮、渡辺龍三東北大学　工学部材料加工学科　980-77　仙台市 Y.Mukaida, A.kawasaki, R.WatanabeDepartment of Materials Processing, Faculty of Engineering, Tohoku University, Sendai 980-77, Japan The burner heating test was carried out with FGM and two layered directly bonded specimens of AlN/W. The surface and bottom temperatures were measured as a function of the output of burner, and the thermal shock damage was monitored with acoustic emission signals liberation. The FGM samples showed an excellent thermal shock behavior, as well as a sufficient heat shield property. The decrease in the thermal conductivity of AlN by the increase of temperature was found to contribute appreciably to the heat insulation. The crack propagation was effectively suppressed with the graded layer. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 111-116 焼結傾斜機能材料の組織とバーナー加熱熱衝撃特性一FGM膜の破壊じん性とき裂伝播に関する基礎検討一 Effect of Microstructure on Cracking of FGMs as Studied by Burner Heating Test - Fracture Toughness and Crack Extension Behavior of FGM coating - 結城正弘1)、中西保正1)、大鍋寿一1)、川崎亮2)、渡辺龍三2)1)石川島播磨重工業(株)　神奈川県横浜市2)東北大学　980-77　仙台市 M.Yuki1), Y.Nakanishi1), H.Ohnabe1), A.Kawasaki2) & R.Watanabe2)M.Yuki1), Y.Nakanishi1), H.Ohnabe1), A.Kawasaki2) & R.Watanabe2) 1) Ishikawajima-Harima Heavy Industries Co., Ltd. Yokohama 235, Japan 2) Tohoku University, Sendai 980-77, Japan The crack extension behavior in the thermal barrier coating made of FGM was investigated based on fracture toughness consideration of sintered PSZ/metal mixtures. It was confirmed that the fracture toughness Kc of sintered PSZ/metal mixtures depended on the microstructures such as the mixed condition of PSZ and metal phase. The Kc of PSZ/IN100 Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 117-122 小麦の傾斜構造と力学特性 Hierarchical gradient structures and mechanical characteristics of wheat 天田重慶1）　O WOO SOCK HENG（ウーソクヘン）2)　清水尚之3)１）群馬大学　教授　2）、3) 　群馬大学　機械工学科　学生群馬県　桐生市 Shigeyasu Amada 1) , Woo Sock Heng 2) , Naoyuki Shimizu 3)1) Professor 2)&3)Students of Gunma University at Department of Mechanical Engineering, Kiryu City, Gunma Pref. , Japan. By observing the appearance of wheat, we can find its culms (stems) are very thin and long. The role of these culms is not only to support the heavy fruits which bear on the top,but also have many mechanical functions to maintain the whole balance against the nature environmental load, for examples, wind loads, rainstorms etc. Those wonderful functional structures have been adapted to our natural environment for so long times. To de-velop a new design and produce a new material in the following century, there is no doubt of clarifying and learning those wonderful functions from our nature. Mankind has long marveled at the efficiency and effectiveness of biologically, evolved structural systems. The mechanical function of wheat's culms which we mentioned above, can be illustrated by observing their macroscopic and microscopic gradient structures. These gradient structures we called "hierarchical gradient structures". The macroscopic gradient structure of wheat's culm can be found by checking out the relation among culm diameter, culm thickness and nodal length with the culm number, respectively [In section 2]. On the other hand, the microscopic gradient structure of culm can be found by observing the internal compositions [In section 3]. The internal composition of wheat's culm has included three components, fibers (bundle sheath), honeycombs and epidermis. The distribution and the strength of these components will play an important role on their mechanical structures. It means that if we can find out the pattern or the rule of those distributions, it may give us a new idea to design or develop a new functionally material, for examples, Functionally Gradient Materials (FGM) etc. This paper is mainly to clarify the hierarchical gradient structures and the mechanical characteristics of wheat's culm by observed its macroscropic and microscropic structures, and wanted to show the interaction between strength and these gradient structures which based on mixture principle. It will give us a chance to understand and learn from the wisdom of our global lives through their features in this modern times. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 123-128 大型供試体の超高温加熱試験技術 Ultra-high Temperature Heating Test of Large-scale Material Sample 石田清道1)、松崎貴至1)、渡辺泰夫1)、芳仲敏成2)、濱村修3)1)航空宇宙技術研究所　182　東京都調布市2)宇宙開発事業団　305　茨城県つくば市3)（株）エイ・イー・エス　茨城県つくば市 K. Ishida 1) , T. Matuzaki 1) , Y. Watanabe 1) ; T. Yoshinaka 2) , O. Hamamura 3)1) Natlonal Aerospace Laboratory, Chofu-city, Tokyo 182, Japan 2) National Space Development Agency of Japan, Tukuba-city, Ibaragi Pref. 305, Japan 3) Advanced Engineering Services,CO.LTD., Tukuba-city, Ibaragi Pref. 305, Japan The 750kW high enthalpy arc-heated wind tunnel at the National Aerospace Laboratory has the capability to test flat plate samples (100mm x100mm ) at tem-peratures of 1000deg.C. For flat plate testing, a channel nozzle was equipped in addition to a usual conical nozzle for stagnation tests. Flow characteristics in the channel nozzle are presented together with performance characteristics of the high performance segmented constricted arc-heater. Some results of material evaluation, utilizing this arc-heater and channal nozzle combination including ACC (Advanced Carbon-Carbon) and refractive ceramictiles are described. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 129-132 熱電変換材料におけるFGMデータベース FGM Data Base for Thermoelectric Materials 須藤孝幸1)、木皿且人1)、毛呂明夫1)1)科学技術庁　航空宇宙技術研究所　角田支所981-15　宮城県角田市君萱小金沢１ T.Sudo 1), K.Kisara 1) , A.Moro 1)1) Kakuda Research Center, National Aerospace Laboratory, STA 1 Koganezawa, Kimigaya, Kakuda Miyagi 981-15 Japan In this paper, method of accumulation and utilization of data for FGM project are presented. The data which have been registered in the data base includes mainly the mechanical property of the heat stress relaxation materials and the thermoelectric property reported in 12th International Conference on Thermoelectrics. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 133-138 傾斜機能熱電変換材料の一次元最適設計 An One-Dimensional Optimum Design of Functionally Gradient Thermoelectric Materials ○寺木潤一1)、平野徹1)1)ダイキン工業（株）MEC研究所　305　茨城県つくば市 Junichi TERAKI 1), Tohru HIRANO 1)1) MEC Laboratory, DAIKlN Industries, LTD., Tsukuba-shi, Ibaraki, 305, Japan The electric function of a material can be improved by application of the FGM concept to the optimization of the carrier conduction mechanism. In Japan the new project for FGM research will focus on energy conversion materials. In this paper, the fundamental design procedure for Functionally Gradient Thermoelectric Materials is presented. At First, a model is presented for the transport properties of heavily doped n-type silicon-germanium alloys. Electron and phonon transport coefficients are calculated using standard Boltzman equation expressions in the relaxation time approximation. Next, we present a finite element analysis of FGM TE device, in terms of a model consisting of "continuously" segmented arms, i.e. arms with a functionally gradient carrier concentration. The energy conversion efficiency is calculated nad compared, spanning temperatures from 300K to 1300K. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 139-142 二元混合傾斜型熱電変換材料のパーコレーション設計 Percolation Design of Two Phase Graded Mixture of Thermoelcctric Materials 渡辺龍三、宮島雅史東北大学工学部　材料加工学科　仙台市 Ryuzo Watanabe, Masafumi MiyajimaDepartment of Materials Processing, Fuculty of Engineering, Tohoku University, Sendai The effect of the percolation transition of the thermoelectric performance of compositionally graded thermoelectric material has been studied by using simple numerical models. The percolation models of the 0th order and the 1st order calculations have been employed in the present analysis, which assume a steep and a gradual percolation transition, respectively. It is shown that the percolation design will realize much higher figure of merit, compared to single phase PbTe or SiGe. The results of numerical calculation and the limitations of the models are discussed. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 143-146 90 Sr RI電池の3層遮蔽構造について Shielding structure for three layer model of heat source of 90Sr radioisotope battery 大橋厚人1)、○植木紘太郎1)、千田哲也2)運輸省　船舶技術研究所　1)原子力技術部　東京都三鷹市2)材料加工部　　東京都三鷹市 A. Ohashi 1), K. Ueki 1), T. Senda 2)1) Nuclear Technology Division, Ship Research Institute, MOT, Mitaka, Tokyo, Japan. 2) Materials and Processing Division, Ship Research Institute, MOT, Mitaka, Tokyo, Japan. We considered how we could reduce the radiation dose of 90Sr radioisotope battery in a condition. Two layers model , with BN layer around a column of SrTiO3, was assumed as a base structure for a heat source of radioisotope battery. Next we thought about three layer structures making a mixing layer between SrTiO3 and BN of the base structure. Comparing three layer structures with the base structure, we calculated how much dose we could reduce using a Monte Carlo code MCNP-4A. In the result, the dose was 17 % off from the base structure to a three structure. In the other hand, this reductive effect corresponded to 1.4 cm thickness of BN of the outside three layer structure and this thickness equaled 10 % of the total weight of the heat source. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 147-152 FGMエネルギー変換材料に基づく宇宙用複合発電システムの性能解析 Performance Analysis of FGM-based Hybrid Energy Conversion System for Space Applications 星野健1),江口邦久2)1) 航空宇宙技術研究所 　東京都調布市2) 宇宙開発事業団　茨城県つくば市 T. Hoshino 1) , K. Eguchi 2)1) National Aerospace Laboratory, Chofu, Tokyo, Japan 2) National Space Development Agency of Japan, Tsukuba, Ibaraki 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 with a cascaded configuration of cesium-filled thermionic and thermoelectric converters. The system may provide a capability of higher conversion efficiency than the other converters for space application. In the present thermodynamic calculations, a simplified model for static power generation is applied. In this model the thermionic converter power is computed by an iterative routine to meet an energy balance for an assumed barrier voltage and so on. On the other hand, thermoelectric converter power is evaluated for a given heat loss and figure of merit (Z) curve. The present paper describes the performance evaluation analysis of hybrid energy conversion system with solar concentrator, and provides the significant considerations for its design requirements. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 153-158 立体形状Re(0001)表面を有する熱電子発電器エミッタ Rhenium with (0001) Surface for Emitter of Thermionic Energy Converter 加藤昌宏1),林武彦1),高岡重彦1〕,五十嵐廉1),福田隆三2)1)東京タングステン(株)　931　富山県富山市2)電子技術総合研究所　305　茨城県つくば市 M.Katoh 1), T.Hayashi 1), S.Takaoka 1) T.Igarashi 1), R.Fukuda 2)1) Tokyo Tungsten Co. ,Ltd., Toyama, Toyama 931 , Japan 2) Electrotechnical Laboratory, Tukuba, Ibaraki 305, Japan In order to improve efficiency of a thermionic energy converter, it is important to develop the emitter electrode with low work function. Rhenium films with (0001) oriented and rugged surface were prepared on molybdenum substrate by chemical vapor deposition. Highly oriented (0001) rhenium has low work function in cesium vapor of the converter and ragged surface has large area of electron emission. Improved efficiency may be expected due to decreasing of barrier index of the converter by these structures. The highly oriented and ragged rhenium films were made from ReCl5 at 1150 to 1350deg.C under pressure of 0.1MPa. The preferential orientation of the surface was identified by X-ray diffraction and electron channeling patterns. Molybdenum diffuses into the rhenium layer to change composition and surface morphology of the layer at high operating temperatures. For thermal stability of the rhenium layer at elevated temperature, graded composition layer was constructed between the rhenium layer and the molybdenum substrate. Graded composition was analyzed with electron probe microanalyzer. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 159-164 PIES法によるBiSbTe系キャリア濃度傾斜構造化材料の熱電特性 Thermoelectric properties of carrier concentration gradient BiSbTe thermoelectric materials prepared by PIES method ○山本淳,太田敏隆,田中忠良電子技術総合研究所　305　茨城県つくば市 Atsushi YAMAMOTO, Toshitaka OHTA, Tadayoshi TANAKAElectrotechnical Laboratory , Tsukuba Ibaraki 305, Japan The carrier concentration gradient p-type BiSbTe thermoelectric material is under consideration in order to actualize larger figure-of-merit value in temperature range from 300K to 500K. The Pulverized and Intermixing Elements Sintering (PIES) method, simple and low-cost powder metallurgy process, was adopted to synthesize the material . Samples which have several different carrier concentrations were prepared and measured thermoelectric properties as base data for designing functionally gradient structure. The p-type (Bi2Te3)0.15 (Sb2Te3)0.85 samples doped with 3-6 at% excess antimony were prepared by PIES method. The wide variation of carrier concentrations from 2.5x10**(25) up to 5.0x10**(26) [m-3] were obtained at room temperature and temperature dependence of figure-of-merit varied correspondently. The maximum dimensionless figure-of-merit value, ZT=0.94 occurred at 390K in 3at% antimony doped sample. As Seebeck coefficients deteriorated at carrier concentration above 1x10**(26) [m-3] , further investigation should be focused on keeping them within order of 1x10**(25) [m-3] . Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 165-170 Bi2Te3系単結晶の熱電気的異方性のキャリア密度依存性 Carrier Concentration Dependence of the Thermoelectric Anisotropies for Bi2Te3-xSex Single Crystals 海部宏昌1),島崎秀樹1),篠原嘉一2),西田勲夫2)1)東京都立大学工学部　192-03　東京都八王子市2)金属材料技術研究所　305　茨城県つくば市 H.T.Kaibe1), Y.Shimazaki1), Y.Shinohara2) and I.A.Nishida2)1)Tokyo Metropolitan University, Hachioji-shi, Tokyo 192-03, Japan 2)National Research Institute for Metals, Tsukuba-shi, Ibaraki 305, Japan The single crystals of n-type Bi2Te2.85Se0.15 doped with different amount of HgBr2 were grown by the Bridgman technique. The carrier concentration of the single crystal doped with 0.02wt% HgBr2 was 4.2x10**(17)cm-3, which is almost two orders less than that of doped with 0.06wt% HgBr2. The anisotropies of the Hall coefficient and the magnetoresistivity decreased with decreasing of carrier concentration. These results indicate that the constant -energy surface transforms from the anisotropic six-valley into more spherical one corresponding to the decrease of the carrier concentration and the increasing of the Se composition. Therefore, it is required to clarify the dependence of anisotropies of the galvanomagnetic parameters such as the resistivity and Hall coefficient on the carrier concentration and Se composition for designing the n-type Bi2Te3 thermoelectric materials with the FGM structure and for analyzing the preferred orientation of crystallites for the hot pressed materials. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 172-176 n型Bi2Te3-Bi2Se3系焼結体の熱電冷却特性 Thermoelectric Cooling Properties of Sintered n-type Bi2Te3-Bi2Se3 System 中村和史1)、大和田仁1)、三浦啓一1)、桑折仁2)、塩田一路3)、西田勲夫4)1)秩父小野田（株）、2)工学院大学　大学院、3)工学院大学、4)金属材料技術研究所 K.Nakamura1) ,H.Owada1) , K.Miura1) , H.Kori2) , I.Shiota3) , I.A.Nishida4)1) Chichibu Onoda Cement Corporation 2) ,3) Kogakuin University 4) National Research Institute for Metals The sintered n-type Bi2Te3-5at%Bi2Se3 and Bi2Te3-10at%Bi2Se3 doped with HgBr2 were prepared by the hot pressing. The pi-shaped unicouples were constructed from the p- and n-type sintered materials. The maximum temperature difference delta Tmax was measured as a function of the hot side temperature in a vacuum or 1x10**-4Torr. The temperature dependence of the figure of merit Zpn was estimated from the temperature of the p-n junction and delta Tmax. Electrical conductivity sigmaand Seebeck coefficient sigma were measured over the temperature range from 100 to 500 K . Thermal conductivity kappa and Hall coefficient R were measured at room temperature. The phonon thermal conductivity (kappa) pn was calculated from kappa - and R- data. The improvement of Zpn for Bi2Te3 was achieved by the increase of Bi2Se3 contents. The improvement was due to the higher power factor sigma 2 sigma and the lower kappa pn by increasing of Bi2Se3 contents. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 177-182 結晶方位分布関数に基づくBi2Te3系焼結材料の熱電特性の異方性解析 Orientation Analysis of the Anisotropic Thermoelectricity of Sintered Bi2Te3 on the Basis of the Orientation Distribution Function 大杉功1)、小島勉1)、坂田亮2)、西田勲夫3)1)育英工業高等専門学校　167　東京都2)杏林大学　181　東京都三鷹市3)金属材料技術研究所　305　茨城県つくば市 I.J. Ohsugi1) , T. Kojima1) , M. Sakata2) , I.A. Nishida3)1) Salesian Polytechnic, Suginami, Tokyo 167, Japan 2) Kyorin University, Mitaka, Tokyo 181, Japan 3) National Research Institute for Metals, Tsukuba, Ibaragi 305, Japan Anisotropic thermoelectric characteristics of a sintered Bi2Te3 system have been evaluated by means of the orientation distribution function. Uniaxial anisotropies in the resistivity, Hall coefficient and thermal conductivities of a sintered Bi2Te3 were expressed as a linear transformation with ananisotropy parameter. X-ray diffraction experiments confirmed thet the observed integral intensities were reasonably consistent with the orientation distribution predicted from the anisotropy parameter. Theoretical curves of resistivities, Hall coefficients and thermal conductivities of sintered material were calculated by using the orientation distribution that was specified by a parameter estimated from the anisotropy in the observed resistivities. The theoretical curves were in reasonable agreement with the observed data. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 183-188 PbSnTe系化合物の結晶育成と熱電特性 Crystal Growth and Thermoelectric Properties of Pb0.75Sn0.25Te 島崎秀樹1),海部宏昌D,奥村次徳1),西田勲夫2〕,今井義雄2〕1)東京都立大学　工学部　192-03　東京都八王子市2)金属材料技術研究所　305　茨城県つくば市 Y.Shimazaki1), H.T.Kaibe1), T.Okumura1), I.A.Nishida2) and Y.Imai2)1)Faculty of Technology, Tokyo Metropolitan University, Hachioji-shi, Tokyo 192-03, Japan 2)National Research Institute for Metals, Tsukuba-shi, Ibaraki 305, Japan Pb0.75Sn0.25Te doped with different amount of PbI2 ranging from 0 to 0.4wt% were synthesized by stirring melt mixtures and unidirectional solidifying using PbTe and SnTe as starting materials prepared by melting weighed amount of each element under liquid B2O3. The Hall coefficient RH and electrical resistivity of the specimens cut out of the each as-grown boule were measured from 55 to 300K. The conduction type of all specimens was p-type, which indicates that the rule of one electron per one molecule of PbI2 can not be applied. A maximum in the variation of RH with temperature was observed for the specimen doped with 0.04wt%PbI2. The result was analysed using a simple two-valence-band model, and the heavy-to-light-mass hole mobility ratio b=micro2/micro1 was 0.18. For the specimen doped with 0.4wt%PbI2, Hall mobility exhibited a S-like curve from 150 to 300K. The small polaron model could be applied and then the hopping energy Eh was obtained to be 0.038eV. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 189-194 低温におけるPbTeの電気伝導温度依存性 Electric Conductivity of Lead-Telluride at Low Temperatures 佐藤浩三1),塩田一路2),西田勲夫3)1)工学院大学　大学院　2)工学院大学　192　東京都八王子市3)金属材料技術研究所　305　茨城県つくば市 K.Sato1),I.Shiota2),I.A.Nishida3)1)Kogaguin University,Hachioji-City,Tokyo 192,Japan. 2)Kogaguin University,Hachioji-City,Tokyo 192,Japan. 3)National Research Institute for Metals,Tsukuba-City,Ibaragi 305,Japan. Lead telluride (PbTe) is a well known thermoelectric material which shows a highest figure of merit at around 700K. However, its properties are hardly known in our country because of few reports. In this paper, grain boundary and carrier concentration effects were investidagated. Effects of grain size were observed for three kinds of p-type specimens with different grain boundaries. First one was prepared by melting and slowly solidifying of mixture of Pb and Te. Second one was fabricated by hot-pressing of PbTe powder. The powder was obtained by pulverizing of a PbTe block which was made in the same process as the first one. Third one was obtained by rapid quenching of molten PbTe. Specific resistivity for the first specimen decreased monotonically from a room temperature to a low temperature. The specific resistivities for second and third samples were as same as the first one at the room temperature, while they increased at the low temperature. The grain size of the first specimen was very large, while the others consisted of very small grains. Therefore the different tendency of the specific resistivity should be caused by the difference of grain boundaries between them. Effects of carrier concentration were also observed for an n-type specimen. It is difficult to fabricate an n- type PbTe due to its extremely narrow compositional range. Then n-type PbTe is usually fabricated by doping of lead di-iodide (PbI2) into molten p-type PbTe. In this experiment, we adopted the traditional method. It was found that the carrier density at the top end of the specimen was approximately 100 times higher than the bottom end. Seebeck coefficient of the bottom end showed a maximum point at 600K, while it was 700K for the top end. It shows that the maximum point of Seebeck coefficient can be shifted by controlling of the carrier density. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 195-200 SiC-B4C系共晶セラミックスの熱電特性 Thermoelectric Properties of SiC-B4C Eutectic Ceramics 後藤孝1)、伊藤永二1)、向田雅一2)、平井敏雄1)1)東北大学　金属材料研究所　980-77　宮城県仙台市2)物質工学工業技術研究所　305　茨城県つくば市 T. Goto1), E. Eiji1), M. Mukaida2), T. Hirai1)1) Institute for Materials Research, Tohoku University, Sendai, Miyagi, 980-77 2) National Institute of Materials and Chemical Research, Tsukuba, Ibaragi, 305 SiC-B4C composites were prepared by arc melting in argon atmosphere using SiC and B4C powders. Uniform lamella texture indicating eutectic reaction was observed at mSic (SiC molar content)= 45 to 50mol%. The thermoelectric figure-of merit valus (Z) were estimated from the Seebeck coefficients, electrical conductivities and thermal conductivities in the temperature range between 400 and 1050K. The SiC-B4C composites near the eutectic composition (at mSic=40mol%) showed the greatest Z values. The Z values increased with increasing temperature. The greatest ZT value was about 0.1 at T=1050K. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 201-206 比誘電率傾斜構造体の平面回路用基板への応用 Application of Dielectric Constant Gradient Structure to Ceramic Substrate ○神波誠治、鷹木洋、川端一也、山田秀章株式会社　村田製作所　617　京都府長岡京市天神2-26-10 S.Kanba, H.Takagi, K.Kawabata, H.YamadaMURATA MFG. CO. , LTD. 2-26-10, Tenjin, Nagaokakyo-shi, Kyoto 617, Japan We report the dielectric constant (epsilon r) gradient structure and its application to a substrate for microwave circuits. The gradient structure is composed of dielectric ceramics with different characteristics. The form of functionally gradient is step-like change of epsilon r. Epsilon r was selected to have optional steps in the range between 6 and 63. We tried to apply the gradient structure to electronic parts. For example, to solve the problem of impedance matching with microwave circuits, we made the ceramic substrate having the epsilon r gradient structure which reduced the size of microwave circuits. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 207-212 有機薄膜EL素子の層界面における傾斜構造と発光効率について Structure and Light Emitting Efficiency of the Organic Thin Film EL Device with Graded Interlayer. 中野辰夫、浅井新一郎電気化学工業総合研究所　194　東京都町田市旭町3-5-1 Tatsuo Nakano and Shin-ichiro AsaiResearch center of Denki Kagaku Kogyo K.K. , 3-5-1 Asahi-cho, Machida City, Tokyo 194, Japan An organic thin film electro-luminescent (EL) device (anode / hole transport layer/ electron-transport and light-emitting layer/ cathode) with a graded interlayer between a hole transport layer and an electron-transport and light-emitting layer was studied. The light emitting efficiency increased with thickness of the graded interlayer till 200 A and then decreased with the thickness. On the other hand, the graded inverse diffusion between the organic layers occured after more than 100 hrs of emission for an EL device without the graded interlayer. It is found that the graded interlayer has an optimum thickness to obtain the maximum light emitting efficiency and that thermal diffusion of molecules between organic layers relates to the life time of the EL device. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 213-218 新型素子を使用した熱電気変換モジュールと発電用サブユニット A subunit of thermoelectric generator composed of new-type modules with single-crystal elements 丹治雍典1　中川康昭2　金子武次郎3　井門秀秋4　久保木實4　古後正徳1　増本健3　佐藤利三郎4１）株式会社　トーキン　R & D Division　982　仙台市２）東北工業大学　982　仙台市３）東北大学　金属材料研究所　980　仙台市４）東北学院大学　工学部　985　多賀城市 Y.Tanji, (1) Y . Nakagawa ,(2) T.Kaneko ,(3) H.Ido,(4) H .Kuboki , (4) N .Kogo, (1) T.Hasumoto, (3) R.Sato, (4)1) R & D Division. Tokin Corporation. Sendai. 982. Japan.2) Faculty of Engineering,Tohoku Institute of Technology,Sedai.982 Japan.3) Institute of Materials Science,Tohoku University.Sendai 980,Japan.4) Faculty of Engineering,Tohoku Gakuin University,Tagajyo,985,Japan. New-type thermoelectric modules composed of 'hamburger' elements (thermoelectric elements sandwitched by copper blocks) are proposed. A compact subunit of thermoelectric generator is manufactured using these mouldes. For the hamburger elements, single crystals of (Bi,Sb)2 (Te,Se)3 compounds are used, which were prepared by the Bridgman method using a new type of crucible. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 219-222 熱電性能評価装置 A Measurement System for Thermoelectric Properties 木皿且人、陳立東、須藤孝幸、熊谷達夫航空宇宙技術研究所　角田宇宙推進技術研究センター K. Kisara, L. Chen, T. Sudo, T. KumagaiNational Aerospace Laboratory,Kakuda Research Center A large-temperature-difference apparatus has been designed and built for thermoelectric performance evaluation of gradiently-segmented thermoelectric 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 temperature span of 800 K. Especially, efforts have been made on controlling axial heat flow pattern under high heat flux and large temperature span conditions. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 223-228 焼結熱電材料の物性推定 Theoretical Calculation of Thermoelectric Figure of Merit for Sintered Materials 吉野淳二東京工業大学　理学部　152　東京都目黒区 Junji YoshinoTokyo Institute of Technology, Meguro-ku, Tokyo 152, Japan Theoretical calculation of thermoelectric figure of merit for sintered materials has been performed based on classical Boltzmann regime. Inter-valley scattering, optical deformation potential scattering and alloy scattering process have been taken into account in addition to the scattering process taken by Vining. The effect of interface on the electric conductivity has been introduced into the calculation based on the heterostructure model. The results indicate that the thermoelectric figure of merit has maximized and been improved about 20 % at the grain size of about 0.1 micro meter. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 229-234 CrSi2単結晶の熱電特性の異方性 Anisotropic Thermoelectricity of a CrSi2 Single Crystal 大杉功1)、小島勉1)、坂田亮,)、西田勲夫3)1)育英工業高等専門学校　167　東京都杉並区2)杏林大学　181　東京都三鷹市3)金属材料技術研究所　305　茨城県つくば市 I.J. Ohsugi1), T. Kojima1), M. Sakata2), I.A. Nishida3)1) Salesian Polytechnlc, Suginami, Tokyo 167, Japan 2) Kyorin University, Mitaka, Tokyo 181, Japan 3) National Rescarch Institute for Metals, Tsukuba, Ibaragi 305, Japan Chromium disilicide is known as a degenerate semiconductor useful for high- temperature applications. The crystal structure of CrSi2 belongs to the hexagonal symmetry group D6h**4, which suggests uniaxially anisotropy. In a CrSi2 single crystal, strong anisotropies about the c-axis was observed in thermoelectric powers as well as resistivities. The anisotropy in thermo-electric power was numerically analyzed by calculating some transport parameters expressed in terms of the Fermi-Dirac integral. The analysis revealed that the acoustic phonon scattering (s I = 0) is dominant in a direction perpendicular to the c-axis, while in the c-direction, dominant is a mixed scattering (s II= 0.7) by acoustic phonons and ionic impurities. Theoretical curves deduced from the anisotropic scattering were in good agreement with the observed data. The results of this analysis were also consistent with those of a magnetic analysis previously performed for the single crystal. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 235-240 SiC/B4C熱電半導体の熱電特性・温度及び密度依存性 Effects of temperature and density on thermoelectric properties of SiC/B4C thermoelectric semiconductor. 岡本庸一、有賀敦、寺本純、宮川浹、藤本司郎防衛大学校　材料物性工学　239　神奈川県横浜市 Y. Okamoto, A. Aruga, J. Morimoto, T. Miyakawa, S. FujimotoNational Defense Academy Dept. of MSE, Yokosuka, Kanagawa 239 Japan We report on the temperature and density dependence of thermoelectric properties of p-type SiC/B4C system for thermoelectric devices. The temperature dependence of electrical resistivity, thermoelectric power and thermal conductivity were measured over the range from room temperature up to 700 deg.C on SiC as a functions of B4C doping concentration over the range 0.2 % - 60 wt. %. The figure of merit in this range increases with temperature by a factor of from 20 to 50. The density dependence of electrical resistivity, thermoelectric power and thermal conductivity were measured on 2 wt. % B4C doped SiC as a function of PSS (Poly-SilaStyrene) concentration over the range 0.5 wt. %-25 wt. %, where PSS acts as the controller of density. We have found that the thermoelectric figure of merit Z of SiC/B4C system at room temperature can be improved by a factor of 10**3 by the addition of PSS. We conclude that the SiC/B4C system with around 20 % of B4C is a promising candidate for thermoelectric applications in the temperature range 400-700 deg.C. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 241-246 傾斜構造をした熱電変換用RI円筒体の温度分布 Temperature Distributions in R.I. Cylinder with Functionally Gradient Structure for Thermoelectric Conversion System 天田重庚1)　○寺内淳一郎1)　渡辺亨1)　千田哲也2)1)群馬大学　工学部　群馬県桐生市2)船舶技術研究所　東京都三鷹市 S.Amada 1) , J. Terauchi 1) , T. Watanabe 1) , T. Senda 2)1) Gunma University , Kiryu-City ,Guuma , Japan 2) Ship Research Institute , Mitaka-City , Tokyo , Japan The power of the thermoelectric generation which is evolved by the thermoelectric conversion is depending on their temperature difference. Therfore, the internal temperature distribution on the thermoelectric generation will play a very important factor. This paper presents an analysis of the temperature distribution by modeling a cylinder, which is combined by the heat source of thermoelectric conversion R. I. : SrTiO3 and shilding material BN. The heat conduction equation in steady-state is applied to this model with the variable thermal conductivity and heat source. The temperature distributions can be found by using the finite differentce equations for the numerical computations. It can be concluded that the model with the proper functional gradient structure has the most highest temperature at the cylinder surface without any melting zone. Japanese １９９４年度　傾斜機能材料論文集　＜ＦＧＭ’９４＞ FY 1994 Proceedings of Functionally Gradient Materials 11 1995-03-01 247-252 スピネル型ZnGa2O4固溶体の組成傾斜と蛍光特性 Gradient composition and fluorescence property in ZnGa2O4 solid solution with spinel structure 遠藤　忠、菊池秀和東北大学　工学部　980-77　宮城県仙台市青葉区 Tadashi Endo and Hidekazu KikuchiTadashi Endo and Hidekazu Kikuchi Fac. of Engrg. Tohoku University, Aoba-ku, Sendai City, Miyagi 980-77 (Zn1-x Mx)Ga2O4 (M=Cd2+, Mn2+) and Zn(Ga1-xMx)2O4 (M=Al3+, Cr3+) were prepared at 1200deg.C for 3 h in air and flowing nitrogen or argon gas. The solid solutions were identified as a single phase with spinel structure. On doping Al3+ and Cd2+ ions, absorption edges were gradually changed with the concentration of dopant. The doped Mn2+ and Cr3+ ions functioned as color centers, corresponding to the 3d-3d transitions. As a result, it was found that the blue emission of ZnGa2O4 was induced by the donor-acceptor recombination due to the gradient and non-stoichiometric compositions. Japanese