# Fileset

[proc-5th-int-symp-fgm-1998-539-793.xlsx](https://mdr.nims.go.jp/filesets/dd8aa425-08f3-46e9-916d-b2b6a3d4d238/download)

## Creator

National Institute for Materials Science

## Rights



## Other metadata

[Functionally Graded Materials 1998　Proceedings of the 5th International symposium on Functionally Graded Materials (pp.539-793)](https://mdr.nims.go.jp/datasets/1de075ed-7b01-4551-821d-a6c64dc3c8ae)

## Fulltext

Sheet1 BookTitle_j BookTitle_e Volume/Issue Issueddate Page Title_j Title_e AuthorList_j AuthorList_e Abstract Language Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 539-543 傾斜機能誘電率を伴う基質の調整と特性評価 Preparation and Characterization of Substrates with Functionally Graded Dielectric Constant 西田俊彦, G. Pezzotti, 塩野剛司京都工芸繊維大学   物質工学科606-8585   京都府京都市左京区松ケ崎御所海道町 T. Nishida, G. Pezzotti and T. ShionoDepartment of Chemistry and Materials Technology, Kyoto Institute of Technology Goshokaido-cho Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan  Preparation of high-frequency band electronic substrates with a significant reduction in the circuit width has been attempted. This purpose has been pursued with the goal of achieving both size reduction and industrial feasibility, and keeping in mind as a design prerequisite that impedance matching with external circuits is a strictly required condition. Two types of powder mixture with different inherent dielectric constant were selected and used as starting materials. Upon adjusting in an appropriate superposition order their alternate layers, a specimen with functionally graded dielectric constant was prepared. After printing a simple circuit geometry on this specimen surface, the high-frequency band wave-transmission loss was measured and showed to be significantly reduced in the functionally graded substrate structure. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 544-548 化学溶液蒸着によって調整した傾斜誘電薄膜 Graded Dielectric Thin Films Prepared by Chemical Solution Deposition S. Hoffmann 2, R. Liedtke 1, R. Slowak 1, U. Hasenkox 1 and R. Waser 1,21 Institut fur Werkstoffe der Elektrotechnik, RWTH Aachen University of Technology, DE-52056 Aachen, Germany 2 Institut fur Eletrokeramische Materialien, IFF, Forschungszentrum Julich, DE-52425 Julich, Germany S. Hoffmann 2, R. Liedtke 1, R. Slowak 1, U. Hasenkox 1 and R. Waser 1,21 Institut fur Werkstoffe der Elektrotechnik, RWTH Aachen University of Technology, DE-52056 Aachen, Germany 2 Institut fur Eletrokeramische Materialien, IFF, Forschungszentrum Julich, DE-52425 Julich, Germany  Columnar structured dielectric (Ba1-xSrx)TiO3 thin films with gradients in composition normal to the growth surface were grown on platinum coated silicon substrates by a chemical solution deposition (CSD) method. The composition gradients were studied by X-ray diffraction analysis and Rutherford backscattering spectrometry, and the film morphology was analyzed by scanning electron microscopy. In the graded thin films the diameter of the grain columns as well as the preferred grain orientation can be tailored by the sequence of the layers. The dielectric properties were analyzed as a function of the composition gradiant and the temperature. The temperature dependence of the capacitance of the graded films, which were contacted in a plate capacitor setup can be simulated by a network of (Ba1-xSrx)TiO3 thin film capacitors in series. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 549-554 組成-傾斜K(Nb、Ta)O3結晶の製造とその誘電特性 Fabrication of Composition-Graded K(Nb,Ta)O3 Crystals and their Dielectric Properties 山根久典　1 , K. Morita　1 2 , 島田昌彦 11 東北大学　素材工学研究所980-8577   宮城県仙台市青葉区片平２丁目１－１2 Current affilation: 太陽誘電株式会社 H. Yamane 1, K. Morita 1,2 and M. Shimada 11 Institute for Advanced Materials Processing, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan 2 Current affilation: Taiyoyuden Co. Ltd.  Composition-graded crystals of K(Ta,Nb)O3 solid solution were prepared by non-equilibrium cooling of melts. The size of the crystals was 0.5 - 2.0 mm. The texture, composition distribution and temperature dependence of dielectric properties were characterized by X-ray diffraction, electron-microprobe analysis, polarizing optical microscopy and impedance analysis. The core was rich in Ta content which decreased gradually in the crystals from the core to the margin, while Nb content increased gradually from the core to the margin. The dielectric properties reflected the composition gradient which depended on the cooling process. The crystals obtained with a higher cooling rate exhibited smaller temperature dependence of dielectric constant. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 555-560 チタン酸化物をもとにした傾斜機能材料の電気・光触媒反応特性 The Electrical and Photocatalysing Properties of a Functionally Graded Material Based on Titanium Oxide 1 渡辺茂男, 保母康雄, 林 二一, 内田悦行, 比嘉俊太郎　2 D. Dykes3 G. Touchard1 愛知工業大学　470-0392　愛知県豊田市八草町八千草１２４７2 四日市大学　512-8045　三重県四日市市萱生町3 Universit・de Poitiers, 40 av. du Recteur Pineau, FR-86022 Poitiers, France S. Watanabe 1, Y. Hobo 1, N. Hayashi 1, Y. Uchida 1, S. Higa 1, D. Dykes 2 and G. Touchard 31 Aichi Institute of Technology, Yachikusa Yakusa-cho Toyota, 470-0392 Japan 2 Yokkaichi University, Kayo-cho, Yokkaichi, 512-8045 Japan 3 Universit・de Poitiers, 40 av. du Recteur Pineau, FR-86022 Poitiers, France  The authors have developed titanium oxide-based functionally graded materials (FGMs) offering special properties of high relative permittivity and photocatalysing capability. In the experiment reported, four such FGMs, sintered at furnace temperatures of 673, 873, 1073 and 1273 K, were examined for their electrical behaviour, particularly relative permittivity and dielectric loss tangent. The measurement frequencies used were 0.25-50 MHz. The paper concludes with a discussion of whether these materials can be used as photocatalyses for the sake of improving the environment. This would open up new applications for FGMs in the area of field relaxation and photocatalysis. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 561-566 高度に強化された高等(Nb，Ti)3Sn超伝導電線と良好なCuNb複合材料安定剤 Advanced (Nb,Ti)3Sn Superconducting Wire with Highly Strengthened and Good Conductive CuNb Composite Stabilizer 渡辺和夫 1,2、本河光博 1,2、T. Onodera 3，5、能登宏七 3、K. Katagiri 3、T. Saito 41　東北大学　金属材料研究所　980‐8577　仙台市2　科学技術振興事業団　戦略的基礎研究推進事業（CREST）3　岩手大学　工学部　020‐8551　盛岡市4　株式会社フジクラ　135‐0042　東京都5　現住所：東北電力株式会社　980‐0811　仙台市 K. Watanabe 1,2, M. Motokawa 1,2, T. Onodera 3,5, K. Noto 3, K. Katagiri 3 and T. Saito 41 Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan 2 CREST, Japan Science and Technology Corporation 3 Faculty of Engineering, Iwate University, Marioka 020-8551, Japan 4 Fujikura Ltd., Tokyo 135-0042, Japan 5 Present address: Tohoku Electric Power Company Inc., Sendai 980-0811, Japan  We developed advanced (Nb,Ti)3Sn multifilamentary superconducting wires with 1 mm in diameter and 3 km in length, which were reinforced and stabilized with Cu-20wt.%Nb composite, CuNb/(Nb,Ti)3Sn. In comparison with practical (Nb,Ti)3Sn wires with conventional Cu stabilizer, Cu/(Nb,Ti)3Sn, it is found that a 0.2 % proof stress of 240 MPa for CuNb/(Nb,Ti)3Sn after heat-treatment at 670 deg.C for 200 h is twice as strong as that for Cu/(Nb,Ti)3Sn. CuNb composite has good thermal conductivity of 200 W/m/K at 4.2 K and low resistivity of 0.16 (mu)(ohm)*cm at 4.2 K and 15 T. The minimum quench energy of 2.7 mJ at 80 % of the critical current at 14 T for CuNb/(Nb,Ti)3Sn is a factor of two smaller than for Cu/(Nb,Ti)3Sn, while the normal zone propagation velocity of 2 m/s remains the same. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 567-572 電界を伴うUV(紫外線)-硬化可能液晶を用いて調整した、傾斜機能工学高分子材料 Functionally Graded Optical Polymer Materials Prepared Using UV-Curable Liquid-Crystals with an Electric Field 佐藤進 1、T. Nose 1、S. Masuda 1,3、梁瀬智 21　秋田大学　電気電子工学科　010　秋田市　2　秋田県高度技術研究所　010 　秋田市　3　現住所：アドバンテスト研究所　989-31、仙台市青葉区上愛子松原48-2 S. Sato 1, T. Nose 1, S. Masuda 1,3 and S. Yanase 21 Akita University, Department of Electrical and Electronic Engineering, Akita, 010 Japan 2 Akita Research Institute of Advanced Technology, Akita, 010 Japan 3 Present address: Advantest Labs., Ltd., 48-2 Matsubara, Kamiayashi, Sendai, 989-31 Japan  UV-curable liquid crystals (LCs) which have a nematic phase at room temperature can be photo-polymerized by ultraviolet (UV) irradiation while holding the molecular orientation state in a nematic phase. Liquid crystal optical devices with a refractive index distribution property are prepared using the novel LC material. After the graded index properties are produced by a nonuniform electric field, the LC is cured with the voltage and the molecular orientation properties in the LC cell are frozen by the UV irradiation; that is, the functionally-graded-polymer devices are formed. Optical polymer devices such as a microlens array and optical waveguide are easily prepared and demonstrated. Each polymer microlens in the lens array has the parabolic graded-refractive-index profile which shows an excellent focusing property. The polymer optical waveguide can also be prepared using a nonuniform electric field distribution produced by a slit patterned electrode structure and loss parameter is estimated for various waveguide structures. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 573-578 窒素プラズマで照射したFe-N傾斜箔の磁気特性 Magnetic Properties of Fe-N Gradient Foils Irradiated with Nitrogen Plasma K. Niizuma and Y. Utsushikawa日本大学　生産工学部　275-8575　千葉県習志野市 K. Niizuma and Y. UtsushikawaCollege of Industrial Technology, Nihon University Narashino, Chiba 275-8575, Japan  We investigated the saturation magnetization and structure of iron foils treated by nitrogen plasma irradiation. The surface of each nitrided foil was removed step by step by electropolishing, and the saturation magnetization of the nitrided foil was then measured. X-ray diffraction patterns were taken from the electropolished surface at each step. Various iron nitrides were formed at all depths of foils nitrided for 5 hours or more, and their quantity increased with the nitriding time. The outermost region of the surface layer irradiated with nitrogen plasma was composed of (gamma)' - Fe4N and (epsilon)- Fe3N, and the inner region was composed of (alpha)' -martensite. The saturation magnetization of  (alpha)' - martensite in a foil nitrided for 13 hours was 223 emu/g. The nitrogen content of  (alpha)' - martensite in the nitrided foil was 0.5 at%. The nitrogen content of  (alpha)' - martensite in the foil nitrided at a surface temperature of 260deg.C with the cathode cooled to 15deg.C was 1.5 at% and 0.5 at% in the nitrided foils when the cathode was not cooled. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 579-584 変形したSUS304ステンレス鋼中でのα’からYへの逆マルテンサイト変換で製造した磁性傾斜機能材料 Magnetic Functionally Graded Material Manufactured with α' to Y Reverse Martensitic Transformation in a Deformed SUS304 Stainless Steel H. Sakai、 D. Morishita、渡辺義見386-8567　長野県上田市常田３丁目１５－１　信州大学 H. Sakai, D. Morishita and Y. WatanabeDepartment of Functional Machinery and Mechanics Shinshu University, 3-15-1 Tokida, Ueda 386-8567, Japan  It is known that the (alpha)' martensite phase in deformed SUS304 stainless steel (Fe-18Cr-8Ni alloy) transforms into (gamma) austenite phase by heating. In contrast to paramagnetism in the austenite phase, the (alpha)' martensite phase shows ferromagnetism. Therefore, heat treatment of deformed SUS304 stainless steel in a thermal gradient is thought to bring about a gradient in the saturation magnetization, with the saturation magnetization depending on local temperature. The present study is aimed at obtaining a suitable gradient of the magnetization by using the (alpha)' to (gamma) reverse transformation in deformed SUS304 stainless steel. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 585-590 共有結合金属窒化物を伴うFeの多層および顆粒状フィルム(膜) Multilayered and Granular Films of Fe with Covalent Metal Nitrides 吉川信一、M. Fujiki、H. Sugiyama、S. Enomoto、高橋昌男大阪大学産業科学研究所　567-0047　大阪府茨木市美穂ケ丘 S. Kikkawa, M. Fujiki, H. Sugiyama, S. Enomoto and M. TakahashiISIR, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan  Rf-sputter deposition was applied to obtain Fe metal/AlN multilayered thin film. Four kinds of the multilayered thin films were deposited at room temperature applying rf-power of 30W or 100W. Both Fe and AlN layers have almost the same thickness and their total film thickness was about 1micrometer. They have stacking sequences of 1, 3, 8 and 35 times, respectively. Larger saturation magnetization in 10 to 20% than that of (alpha)-Fe was observed on the multilayers in 3 and 8 times stacking. Larger internal magnetic field component in about 10% than that of (alpha)-Fe was present in Mossbauer spectra for these films. The giant magnetization was much clear on the multilayered films prepared at rf-power of 100W. AlN was assumed to react slightly with (alpha) - Fe at the multilayered interface supplying a small amount of nitrogen into a bcc Fe lattice to form Fe16N2 related material in nitrogen concentration graded interface. Reactive rf-sputter deposition was also applied on Fe-Al-N ternary thin film deposition to obtain granular films. New wurtzite-type solid solution of Al1-xFexN (x<30atm%) was observed on all as-deposited films. Defect rock salt-type (gamma)"-FeN coexisted in the films with composition above the solid solution limit. Granular film where (alpha)-Fe particle dispersed in amorphous matrix was obtained by annealing of the films with chemical composition above the solid solution limit in H2 flow at 500deg.C. They showed soft ferromagnetic behavior. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 591-596 少量の高分子(ポリマー)を用いた傾斜率型液晶マイクロレンズ Graded Index Type Liquid Crystal Microlens Using Small Amount of Polymer H. Kusanagi 1, S. Masuda 2, T. Nose 1 and 佐藤進11　秋田大学　電気電子工学科　010　秋田市　2　現住所：989-31、仙台市青葉区上愛子松原48-2　アドバンテスト研究所 H. Kusanagi 1, S. Masuda 2, T. Nose 1 and S. Sato 11 Department of Electrical and Electronic Engineering Akita University, Akita, 010 Japan 2 Present address: Advantest Laboratories, Ltd., 48-2 Matsubara, Kamiayashi, Sendai, 989-31, Japan  Liquid Crystal (LC) microlens which has a graded index property can be attained by using the LC cell with a simple circular hole-patterned electrode which gives an inhomogeneous electric field distribution. The index distribution profile is normally determined by the molecular orientational state in the LC cell which is exactly defined by the combined effects of the substrate boundary and applied electric field. Although the LC microlens can supply a variable focusing property, it usually requires a long response time for the driving voltage. In this work we tried to utilize an extra molecular orientational effect by introducing a small content of UV curable materials and forming a polymer network by UV irradiation in a LC cell for improving electro-optical properties. We have investigated a various optical and electro-optical properties of the LC microlens by adopting up to 20 wt% of polymer concentration. Improvements of the response property and holding effects of gradient index properties can be obtained by optimizing the polymer concentration, alignment layer and other fabricating condition. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 597-602 高輝度シンクロトロン光線(ビーム)における使用のためのSi1-xGex側面方向に傾斜した結晶の検査 Examination of Si1-xGex Laterally Graded Crystals for Use in High Brilliance Synchrotron Beams M. Veldkamp 1, A. Erko 1, F. Schafers 1, W. Gudat 1, N. Abrosimov 2, V. Alex 2, S. Rossolenko 2, V. Shekhtman 3, E. Shulakov 3, S. Khasanov 3 and l. Smirnova 31 BESSY mbH, Rudower Chaussee 5, DE-12489 Berlin, Germany 2 Institute of Crystal Growth Berlin, Rudower Chaussee 6, DE-12489 Berlin, Germany 3 Institute of Solid State Physics RAS, RU-142432 Chernogolovka, Russia M. Veldkamp 1, A. Erko 1, F. Schafers 1, W. Gudat 1, N. Abrosimov 2, V. Alex 2, S. Rossolenko 2, V. Shekhtman 3, E. Shulakov 3, S. Khasanov 3 and l. Smirnova 31 BESSY mbH, Rudower Chaussee 5, DE-12489 Berlin, Germany 2 Institute of Crystal Growth Berlin, Rudower Chaussee 6, DE-12489 Berlin, Germany 3 Institute of Solid State Physics RAS, RU-142432 Chernogolovka, Russia  We report about the feasibility of employing laterally graded Si1-xGex crystals as x-ray monochromators for synchrotron radiation beams. This type of crystals can be used in a divergent beam with nearly the same energy resolution and spectral flux as a regular crystal in a parallel beam. The effect is achieved due to continous changes in the lattice parameter with varying Ge concentration in the Si crystal. Theoretical calculations for BESSY II dipole radiation show, that the optimum gradient of Ge along the surface should be about 1.0 at. % per cm. The properties of the crystals have been investigated by x-ray diffraction and fluorescence analysis with radiation from a conventional x-ray tube. We found nearly perfect crystal quality for Ge concentrations up to 7.0 at. % and gradients of Ge up to 1.1 at. % Ge per cm which would already be sufficient for applications in the x-ray monochromator. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 603-607 融合原子炉中での切換え器プレート組成物質のための傾斜機能W‐Cu材料の微少機構モデル Micromechanical Modelling of Functionally Graded W-Cu Materials for Divertor Plate Components in a Fusion Reactor M. M. Gasik 1、S. Ueda1 Helsinki University of Technology, Fl-02015 HUT, Finland 2　東北大学　 980-8579　仙台市 M. M. Gasik 1 and S. Ueda 21 Helsinki University of Technology, Fl-02015 HUT, Finland 2 Tohoku University, Sendai 980-8579, Japan  Thermonuclear fusion process implementation has many materials problems and one of them is related to removal of impurities from plasma. In the International Thermonuclear Experimental Reactor (ITER), a divertor concept has been incorporated for this purpose. In this work, the development of a micromechanical model for FGM is presented and its application to thermal-elasto-plastic analysis is discussed for the case of W-Cu FGM for ITER divertor plates. The model allows the prediction of basic properties of 3-D FGM, computations of thermal stresses, and, in some limits, it may be used for pre-design evaluation of dynamic strain/stress distribution and inelastic behaviour. The model is found to be very useful at the first stages of graded materials design and computation of properties in the nodal points for more detailed numerical analysis. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 608-613 高分子材料を負荷した傾斜機能カーボンブラック Functionally Graded Carbon Black Loaded Polymeric Materials V. BoudaCzech TU, Electrical Engineering Faculty, Department of Mechanics and Material Science, Technicka 2, CZ-16627 Praha 6, Czech Republic V. BoudaCzech TU, Electrical Engineering Faculty, Department of Mechanics and Material Science, Technicka 2, CZ-16627 Praha 6, Czech Republic  Interest in carbon black (CB) loaded composite plastics is connected with the easy of changing their conductivity and permittivity in broad intervals by changing the CB-concentration. However, the processing technology shows also a significant effect on the conductivity and permittivity of the composite material in broad intervals of several orders of magnitudes at the same CB-concentration. The creation of the CB-conductive network, the reversible or irreversible dispersion of CB-particles can result -from specific processing technologies respectively. A local level of conductivity and permittivity can be achieved by a local control of the electrostatic repulsion potential between the CB-particles. This is facilitated e. g. by consecutive changing of the local temperature and/or external direct or alternating electrical fields. Understanding of the specific processing technology can lead to new applications in two ways: in selectively increased conductivity (e. g. conductive and isolation paths in electrical circuits in polymer films) and in new supercapacitors. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 614-621 傾斜機能セラミック/金属アップリケの開発と弾道テスト Development and Ballistic Testing of a Functionally Gradient Ceramic/Metal Applique W. A. Gooch 1, B. H. C. Chen 2, M. S. Burkins 1, R. Palicka 2, J. Rubin 2 and R. Ravichandran 31 U. S. Army Research Laboratory, Aberdeen Proving Ground, MD 21005-5066, USA 2 Cercom Incorporated, 1960 Watson Way, Vista, CA, 92083, USA 3 University of Utah, Department of Metallurgical Engineering, Salt Lake City, UT, 84112, USA W. A. Gooch 1, B. H. C. Chen 2, M. S. Burkins 1, R. Palicka 2, J. Rubin 2 and R. Ravichandran 31 U. S. Army Research Laboratory, Aberdeen Proving Ground, MD 21005-5066, USA 2 Cercom Incorporated, 1960 Watson Way, Vista, CA, 92083, USA 3 University of Utah, Department of Metallurgical Engineering, Salt Lake City, UT, 84112, USA  The U. S. Army Research Laboratory has undertaken a two year Small Business Initiative Research program with Cercom Incorporated to develop a ballistic applique that transitions from a ceramic cermet hard face to a metal back face which can be fabricated to near net shape during the densification process. These functionally gradient materials offer significant advantages in armor applications over conventional adhesive bonded ceramic-metal appliques. This paper will discuss the conceptional requirements, material development process and highlight the 14.5-mm ballistic testing conducted to date. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 622-627 衝撃下の材料の均質および不均質作用 Behaviour Isotropic and Anisotropic of Materials under Impact A. V. Radchenko and S. V. KobenkoTomsk Branch of the Institute for Structural Macrokinetics of Russian Academy of Sciences, Tomsk, Russia A. V. Radchenko and S. V. KobenkoTomsk Branch of the Institute for Structural Macrokinetics of Russian Academy of Sciences, Tomsk, Russia  Development of modern materials production technologies with the given orientation of physico-mechanical and the increasing requirements imposing to optimization and reliability of the operational characteristics of designs, cause the increased interest to the investigations of anisotropic materials behavior in various conditions.       The distinctions in structure and technologies of anisotropic materials creation also predetermine their essential qualitative distinctions in response toward external loading. It results in necessity of complex experimental and theoretical approach to a problem. However, investigations in this direction are carried out basically for static conditions of load. The behavior of anisotropic materials under the conditions of dynamic loading is practically not investigated. This is especially the case with experimental investigations as well as with mathematical and numerical modeling.       The investigations of the material damage under impact show that the destruction mechanisms change with the interaction conditions. But in the experiments we fail to trace sequence, operation time and the contribution of various destruction mechanisms. Besides, the distractions, obtained at the initial stages of the process can't always be identified in the analysis of the resulting destruction of the materials. For anisotropic materials the strength itself is multivalued and uncertain notion due to the polymorphism of behaviour of these materials under the load. The limiting state of anisotropic bodies may be of different physical nature in dependence on load orientation, stressed state type and other factors. The dependence of the physical nature of limiting states is revealed in the study of the experimental data.       Phenomenological approach to the investigation of dynamics of deformation and destruction of anisotropic and isotropic materials is used in the work. The phenomenological approach to the materials strength requires that the conditions of the transition into the limiting state of various physical nature should be determinated by one equation (criterion). The necessity of such an approach results from destruction polymorphism, being deduced experimentally. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 629-633 密度勾配を伴うW‐Mo傾斜機能材料の製造 Fabrication of W-Mo Functionally Graded Material with Density Gradient H. Xiong, L. Zhang, J. Li, H. Tao and R. YuanState Key Lab. of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, R. P. China H. Xiong, L. Zhang, J. Li, H. Tao and R. YuanState Key Lab. of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, R. P. China  W-Mo system functionally graded material with density gradient, which can be applied to dynamic high-pressure technology, was prepared by hot-pressing at 1573K. In order to obtain fully dense body, suitable amount of Ni and Cu was added. The FGM has quasi-continuous density variation in the thickness direction. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 634-638 熱鍛造応用のための傾斜機能鋳造工具 Functionally Graded Cast Tools for Hot Forging Applications C. Pelz 1, H. Haferkamp 1, Fr.-W. Bach 2 and M. Niemeyer1 Institute of Materials Science, University of Hanover, Germany 2 Institute of Materials Engineering, University of Dortmund, Germany C. Pelz 1, H. Haferkamp 1, Fr.-W. Bach 2 and M. Niemeyer1 Institute of Materials Science, University of Hanover, Germany 2 Institute of Materials Engineering, University of Dortmund, Germany  During hot forging the forging dies are exposed to high charges consisting of pressure, heat changes, wear, shear stress and bending fatigue. These charges affect only a zone near the sinking where an expensive and resistant hot work tool steel is required. For the die body a cheaper steel with higher caloric conductibility and toughness would be desirable.      To receive this effect the Institute of Materials Science at the University of Hanover developed a compound casting method which allows to join different alloys by sand casting steel melt on cold solid inserts.       Analytical studies have shown that the joint zones exhibit a continuos gradient of chemical composition, microstructure and mechanical-technological properties aimed to the demand of hot forging. The usability of the functionally graded forging dies is tested under forging conditions and on the basis of the graded structure, a high lifetime can be attained. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 641-646 傾斜機能熱電材料のための計算デザイン Computational Design for Functionally Graded Thermoelectric Materials 平野徹1、寺木潤一1、西尾好正21　ダイキン工業株式会社　電子技術研究所　525-0044　滋賀県草津市岡本町1000-22　ダイキン工業株式会社　3電子技術研究所　05-0841　茨城県つくば市御幸が丘3 T. Hirano 1, J. Teraki 1 and Y. Nishio 21 Electronic Engineering Laboratory, Daikin Industries, Ltd., 1000-2, Okamotocho, Kusatsu-shi, Shiga, 525-0044, Japan 2 Electronic Engineering Laboratory, Daikin Industries, Ltd., 3, Miyukigaoka, Tsukuba-shi, Ibaraki, 305-0841, Japan  In order to improve the conversion efficiency of thermoelectric (TE) materials and devices, computational study was performed for two different concepts of FGM configuration.      (1) TE FGM Power Device with Graded Dopant Density       In order to design optimum dopant density distribution, precise estimation of transport properties and optimization of the carrier conduction mechanism are required. A model of thermoelectric materials is presented for transport properties of heavily doped semiconductors, and electron/phonon transport coefficients are estimated using band theory. Then, optimum dopant distribution is calculated in view of maximizing energy conversion efficiency. Simultaneously, thermal stresses induced by the high temperature gradient within the TE device should be reduced. Since the internal physics is a coupled phenomena of heat flux and electric current, 2D Finite Element Method (FEM) is applied for the coupled analyses. The thermal stresses are calculated by 2D plane strain FEM for 3 stage cascade and segmented modules.      (2) Multi-layered Thermoelectric Material with Graded Potential Barriers       A very different approach to increase the conversion efficiency is utilization of potential barriers. Since potential barriers act as carrier energy filters, elimination of lower energy carriers results in an improvement of the efficiency of thermoelectric energy conversion (energy filtering method). It has been shown that the characteristic energy range of carriers can be defined for thermoelectric energy conversion. From the knowledge of this characteristic energy range, the concept of graded control of microscopic physical quantities for optimizing the efficiency is clarified. The optimal height of potential barriers and the distance between the barriers are estimated within a semi-classical framework, i. e. using Boltzmann equation. The method of improving the efficiency by using the multi-layered materials is proposed and the graded design of barrier layers is presented. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 647-652 傾斜熱電材料の組成機能に関して On the Composition Function of Graded Thermoelectric Materials J. Schilz 1, E. Muller 1, L. Helmers 1, 康燕生 2、野田泰稔3、新野正之 21 German Aerospace Center (DLR), Institute of Materials Research, DE-51170 Koln, Germany 2　航空宇宙技術研究所　角田宇宙推進技術研究センター　981-1525　宮城県角田市君萱小金沢13　島根大学総合理工学部　690-8504　島根県松江市西川津町１０６０ J. Schilz 1, E. Muller 1, L. Helmers 1, Y. S. Kang 2, Y. Noda 3 and M. Niino 21 German Aerospace Center (DLR), Institute of Materials Research, DE-51170 Koln, Germany 2 National Aerospace Laboratory (NAL), Kakuda Research Center, Koganezawa 1, Kimigaya, Kakuda City, Miyagi-Pref. 981-1525, Japan 3 Shimane University, Faculty of Science and Engineering, Department of Materials Science, Nishi-Kawazucho 1060, Matsue 690-8504, Japan  It is well known that the performance of a thermoelectric generator can be enhanced by choosing temperature-adapted concentration profiles along the TE legs. Several procedures have been published which are able to obtain a particular profile (out of a given set of materials) that maximizes the efficiency or the electrical power output. However, the role of the temperature dependent figure-of-merit, Z, in performance enhancement is still a contentious issue.       We will show here that from a theoretical standpoint a local Z-maximization is not correct for efficiency enhancement. Our recently developed numerical tool for the performance description of arbitrarily composed TE-generators will be used to illustrate this. But: The derived results allow the conclusion that in spite of the wrong theory, a local Z-maximization can be applied if this leads to a "homogenization" of the overall temperature dependence of Z. Regarding the practical case of designing a stacked generator, the already common procedure to place the material junctions at the Z-curve intersections is thus a posteriori justified.       For the electrical power output, however, a different situation occurs. Though there seems to be no local criterion for efficiency enhancement of a graded TE-generator, we show that such a measure for output power maximization indeed exists. An example of a stacked Bi-Te/FeSi2-generator is given. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 653-658 FGMコンプライアンスパッドの使用による高エネルギー密度の熱電エネルギー変換ユニットのデザイン Design of High Energy Density Thermoelectric Energy Conversion Unit by Using FGM Compliant Pads 神戸満財団法人　電力中央研究所　(CRIEPI)　201-8511　東京都狛江市岩戸北２丁目１１－１ M. KambeCentral Research Institute of Electric Power Industry (CRIEPI), 11-1, Iwado Kita 2-chome, Komae-shi, Tokyo 201-8511, Japan  In order to provide increasingly large amounts of electrical power to space and terrestrial systems with a sufficiently high level of reliability at a reasonable cost, thermoelectric (TE) energy conversion system by using Functionally Graded Material (FGM) compliant pads has been focused.       To achieve high thermal energy density in TE power conversion systems, conductively coupling the TE units to the hot and cold heat exchangers is the most effective configuration. This is accomplished by two sets of FGM compliant pads. This design strategy provides (1) a high flux, direct conduction path to heat source and heat sink, (2) the structural flexibility to protect the cell from high stress due to thermal expansion, (3) an extended durability by a simple FGM structure, and (4) manufacturing cost reduction by spark plasma sintering.       High thermal energy density of ten times as much as conventional radioisotope thermoelectric generator is expected. Manufacturing of Cu/Al2O3/Cu symmetrical FGM compliant pads by spark plasma sintering (SPS) and overall assembling of TE unit are also discussed. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 659-664 Geでドープした焼結済みSiCの熱電特性 Thermoelectric Properties of Sintered SiC Doped with Ge 稲井博志、岡本庸、守本純防衛大学校　材料物性工学　239-8686 　神奈川県横須賀市走水１丁目１０－２０ H. Inai, Y. Okamoto and J. MorimotoDept. of Materials Science and Engineering, National Defense Academy, Hashirimizu 1-10-20, Yokosuka, Kanagawa 239-8686, Japan  Silicon carbide is a promising thermoelectric ceramics material to be used in the high temperature region. However, it has large electrical resistivity and large thermal conductivity. These properties are not desirable for the thermoelectric devices. In this paper, Ge was selected as an additional material to reduce the thermal conductivity. The thermoelectric properties of SiC/Ge system have been studied over the temperature range from room temperature to 750deg.C as a function of Ge concentration (1.0 wt.%-40.0 wt.%). The figure of merit is estimated from thermal conductivity, electrical resistivity and Seebeck coefficient. The thermal conductivity decreases with temperature and Ge concentration increases. The thermal conductivity of the sample with Ge 40.0 wt.% is 8.0 W/mK at around 300deg. C. The electrical resistivity is larger by two order than our other metallic element doped samples such as Ni, Ag, Cu and Al. The figure of merit of the that sample is estimated about 2.0 * 10**-5 K-1 at around 750deg.C. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 665-668 異なったキャリア濃度を伴う2-セグメントn-PbTeの最大電力上のセグメント長さの効果 Effect of Segment Length on Maximum Power of 2-Segmented n-PbTe with Different Carrier Concentrations 今井義雄、篠原嘉一、磯田幸宏、西田勲夫科学技術庁 金属材料技術研究所　305-0047　茨城県つくば市千現1-2-1 Y. Imai, Y. Shinohara, Y. Isoda and I. A. NishidaThe 4th National Research Institute for Metals, STA, 1-2-1, Sengen, Tsukuba-shi 305-0047, Japan  The n-PbTe joined compacts of two segments with carrier concentration ne of 1 * 10**25 and 3 * 10**25/m3 have been fabricated by hot pressing, and the effective maximum power Pmax has been evaluated in relation to the length ratio X of the segment (ne=1 * 10**25/m3) to the joined compact. X was changed to be 44, 50 and 62%. The Pmax of the joined compact was between the Pmax curves of the two segments at (delta)Thc<=420-480K, while was larger at (delta)Thc>=420-480K. (delta)Thc is the temperature difference between the hot and the cool side temperatures. The optimum interface temperature of the joined compact was 640K. When (delta)Thc=500K and also X=75%, Ti was 640K. The joined compact with X=75% was expected to generate 10% more power than the homogeneous compacts at (delta)Thc=500K. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 669-674 傾斜機能材料における以上に高いエネルギー移動の新しい機構 The New Mechanism of Abnormally High Energy Transferring in Functionally Graded Materials Y. Bilotsky 1 and M. M. Gasik 21 Institute of Physics, UA-252650 Kyiv, Ukraine 2 Helsinki University of Technology, FI-02015 HUT, Finland Y. Bilotsky 1 and M. M. Gasik 21 Institute of Physics, UA-252650 Kyiv, Ukraine 2 Helsinki University of Technology, FI-02015 HUT, Finland  The functionally graded materials (FGMs) are characterised by a 3D-distribution of phases and corresponding properties and their physical behaviour often cannot be explained or described by conventional theoretical approaches, used for isotropic materials.       In this work, the new description of abnormally high energy transfer in space-limited graded structures is suggested based on the peculiarities of photon-electron-phonon interaction. FGM with fine arranged inclusions may have an ultra-high velocity of energy transfer due to presence of hot electrons in metals. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 675-680 プラズマ活性焼結によって連結したNi/n-PbTeおよびNi/p-Pb0.5Sn0.5Teの電気特性 Electric Properties of Ni/n-PbTe and Ni/p-Pb0.5Sn0.5Te Joined by Plasma Activated Sintering 折橋正樹4、野田泰稔2、陳立東 1、康燕生 3、毛呂明夫3、平井敏雄11　東北大学　金属材料研究所　980-8577　宮城県仙台市青葉区片平２丁目１－１2　島根大学総合理工学部　690-8504　島根県松江市西川津町１０６０3　 航空宇宙技術研究所　角田宇宙推進技術研究センター　981-1525　宮城県角田市4　日本学術振興会、JSPS特別研究員 M. Orihashi 1, 4, Y. Noda 2, L. Chen 1, Y. -S. Kang 3, A. Moro 3 and T. Hirai 11 Institute for Materials Research, Tohoku University, 2-1-1, Sendai, Miyagi 980-8577, Japan 2 Faculty of Science and Engineering, Shimane University, Matsue, Shimane 690-8504, Japan 3 National Aerospace Laboratory, Kakuda Research Center, Kakuda, Miyagi 981-1525, Japan 4 Research Fellow of Japan Society for the Promotion of Science (JSPS Research Fellow)  In order to fabricate PbTe thermoelectric elements, Ni electrodes were joined with n-PbTe and p-Pb0.5Sn0.5Te by plasma activated sintering (PAS). The characterization of the Ni/n-PbTe and Ni/p-Pb0.5Sn0.5Te junctions was carried out by measuring voltage distribution around the joint boundary. No potential voltage gap was found at the interface of Ni/n-PbTe joint. In the case of Ni/p-Pb0.5Sn0.5Te joint, a large potential gap was found at the interface, where the intermediate layer with complicated composition was detected by EPMA. A buffer layer of p-SnTe was introduced into the Ni/p-Pb0.5Sn0.5Te joint to reduce the interface resistivity between Ni and p-Pb0.5Sn0.5Te. Low resistivity joint of metal/semiconductor was obtained by insertion of p-SnTe between Ni and p-Pb0.5Sn0.5Te. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 681-686 傾斜FeSi2熱電元素－混合添加物焼結による調整 Graded FeSi2 Thermoelectric Elements - Preparation by Intermixed Additives Sintering E. Muller, K. Schackenberg, J. Schilz and W. A. KaysserGerman Aerospace Center - DLR, Institute of Materials Research, DE-51 170 Koln, Germany E. Muller, K. Schackenberg, J. Schilz and W. A. KaysserGerman Aerospace Center - DLR, Institute of Materials Research, DE-51 170 Koln, Germany  Iron disilicide is a well established material for the fabrication of thermoelectric (TE) generators and it is promising for thermal sensors, as well. The conversion efficiency of a thermogenerator can be increased by grading (or segmenting) the TE properties. For sensors, a widening of the temperature range and linearisation of characteristics can be achieved by a graded design.       For p- and n-type doping of FeSi2, there is a multitude of elemental electrically active impurities available. In order to optimise the doping concentration with regard to TE performance at different working temperatures, a new method referred to as Doping by Intermixed Additives Sintering (DIAS) has been identified as a simple instrumentality.       Starting from gas atomised FeSi2 powder and elemental additives (Al, Mn) we used a planetary ball mill for grinding and intermixing the components. After hot pressing, a high temperature treatment is necessary to incorporate the dopants onto lattice positions where they are electrically active as donors or acceptors. The resulting transport properties of homogeneous samples have been measured.       Segmented TE elements have been built up by hot pressing of stacked layers. FeSi2 powders with different concentration of intermixed dopants have been prepared and stacked with subsequently increasing doping content. A real case test under large temperature difference conditions has been performed on a DIAS made stacked thermogenerator element.      The preparation of functionally graded thermal sensors for high temperature application from FeSi2 is discussed to be very promising. Technological pre-conditions have been established to give good chances to their realisation. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 687-692 FGM熱電素子についてのドーピングレベルと焼結条件のための熱電特性制御 Thermoelectric Properties Control Due to Doping Level and Sintering Conditions for FGM Thermoelectric Element 梶川武信1、志田啓亮1、白石健太郎、大森守2、平井敏雄21　湘南工科大学　電気工学科　神奈川県藤沢市2　東北大学　金属材料研究所　宮城県仙台市 T. Kajikawa 1, K. Shida 1, K. Shiraishi 1, M. Ohmori 2 and T. Hirai 21 Shonan Institute of Technology, Department of Electrical Engineering, Fujisawa, Kanagawa, Japan 2 Institute For Materials Research, Tohoku University, Sendai, Miyagi, Japan  Thermoelectric performance is determined with three factors, namely, Seebeck coefficient, electrical resistivity and thermal conductivity. For metal and single crystalline semiconductor, those factors have close interrelation each other. However, as the sintered thermoelectric element has various levels of superstructure from macro scale and micro scale in terms of the thermoelectric mechanism, the relationship among them is more complex than that for the melt-grown element, so it is suggested that the control of the temperature dependence of thermoelectric properties is possible to enhance the thermoelectric performance for wide temperature range due to FGM approach. The research objective is to investigate the characteristics of the thermoelectric properties for various doping levels and hot-pressed conditions to make the thermoelectric elements for which the temperature dependence of the performance is controlled due to FGM approach varying the doping levels and sintering conditions. By usage of the zone traveling hot-press sintering method to Antimony doped magnesium silicide synthesized by the spark plasma sintering method the continuously, functionally graded, sintered thermoelectric bulk element could be successfully made, and the distribution characteristics of thermoelectric properties were satisfactorily measured. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 693-698 FGM形成によるBi2Te3/PbTeの利用温度範囲の拡張 Expansion of Utilizing Temperature Range of Bi2Te3/PbTe by FGM Forming 腰越美営1、塩田一路1、西田勲夫21　工学院大学　192-0015　東京都八王子市2　金属材料技術研究所　305-0047　茨城県つくば市 M. Koshigoe 1, I. Shiota 1 and I. A. Nishida 21 Kogakuin University, Hachioji, Tokyo 192-0015, Japan 2 National Research Institute for Metals, Tsukuba, Ibaraki 305-0047, Japan  FGM forming is one of promising methods to improve the efficiency of thermoelectric materials. Soldering is the most simple and feasible method to join thermoelectric materials. However, durability of the joined material at a high temperature is important for practical application. The purpose of this study is joining of Bi-Te and Pb-Te for expansion of utilizing temperature range with high performance by soldering. Te-Ag eutectic alloy (m. p. 624K) was used as the solder. The FGM showed higher power factor than each monolithic material at the temperature range between 400K and 650K. Thermal stability of the joined material was investigated. It was found that the properties of the segmented FGM deteriorated after the joined part was heated over 520K. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 699-703 液相拡散結合によるPb1-xSnxTe FGMの熱電特性 Thermoelectric Properties of Pb1-xSnxTe FGM by Liquid Phase Diffusion Bonding 橋本政靖1、大橋修1、塩田一路2、海部宏昌 3、西田勲夫41　新潟大学　大学院生　950-2181　新潟県新潟市五十嵐２の町８０５０2　工学院大学　192-0015　東京都八王子市中野町2665-13　東京都立大学　192-0397　東京都八王子市南大沢１丁目１4　金属材料技術研究所　305-0047　茨城県つくば市千現1-2-1 M. Hashimoto 1, O. Ohashi 1, I. Shiota 2, H. T. Kaibe 3 and I. A. Nishida 41 Niigata University, Grad., 8050 Igarashi 2-no-cyo, Niigata, Niigata 9502181, Japan 2 Kogakuin University, 2665-1 Nakano, Hachioji, Tokyo 1920015, Japan 3 Tokyo Metropolitan University, 1-1 Minami-Ohsawa, Haichioji, Tokyo 1920397, Japan 4 National Research Institute for Metals, 1-2-1 Sengen, Tsukuba, Ibaraki 3050047, Japan  The stoichiometric PbTe and SnTe, and their solid solution, Pb1-xSnxTe were prepared in a rocking-freezing furnace with rocking cycle of 0.2Hz. The carrier concentration was increased and the temperature with maximum figure-of-merit shifted to higher side with increasing of x in Pb1-xSnxTe. A segmented thermoelectric material with different carrier concentration is expected to have high performance. A segmented thermoelectric material of PbTe system with different carrier concentration was fabricated by liquid phase diffusion bonding in this study.       The joining was performed under 2.0MPa at 700K for 1800s in an Ar atmosphere. The segmented material had an basic and the most primitive FGM structure. The bonding was strong enough and the electrical resistance at the interface was very low. The segmented material showed a higher effective maximum power Pmax than each monolithic material over the observed temperature range. The Pmax for the segmented material agreed with the theoretically expected result from the properties of monolithic materials and is 23Wm-1 at (delta)T=330K. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 704-710 多結晶テルル化鉛*　へのZn+イオン注入の熱電特性 Thermoelectric Properties on Zn+ Ion Implantation into Polycrystalline Lead Telluride* L. Zhang 1, J. Li 1, G. Wang 1, J. Li 2 and M. Ye 21 State Key Lab. of Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, R. P. China 2 Department of Physics, Wuhan University, Wuhan 430072, R. P. China L. Zhang 1, J. Li 1, G. Wang 1, J. Li 2 and M. Ye 21 State Key Lab. of Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, R. P. China 2 Department of Physics, Wuhan University, Wuhan 430072, R. P. China  PbTe is a useful thermoelectric material for the design of functionally graded materials (FGM) thermoelectric device. Since the maximum figure of merit shifts in a wide temperature range depending upon carrier concentration, the stepwise carrier concentration FGM of PbTe is expected to attain high efficiency of thermoelectric energy conversion. In order to improve the carrier concentration profile, 110 KeV Zn+ ions were implanted into n-type PbTe samples. X-ray diffraction (XRD) has been used to examine the effect of ions implantation on the structure of PbTe. By varying the ion dose it is possible to investigate the Zn-PbTe phase relationship, and the effect of forming a joint boundary on the thermoelectric properties of PbTe. Electrical resistance and Hall coefficient measurements have also been carried out as a function of implantation dose at room temperature. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 711-716 FGMデザイン*におけるn-型PbTeの熱電特性へのSn+イオン注入および注入後焼きなましの効果 Effects of Sn+ Ion Implantation and Post-Implantation Annealing on the Thermoelectric Properties of n-Type PbTe in FGM Design* Q. Shen 1, L. Zhang 1, G. Wang 1, 陳立東 2, R. Tu 2 and 平井敏雄 21 State Key Lab. of Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, R. P. China 2 　東北大学 金属材料研究所　980-8577 宮城県仙台市青葉区片平２丁目１－１ Q. Shen 1, L. Zhang 1, G. Wang 1, L. Chen 2, R. Tu 2 and T. Hirai 21 State Key Lab. of Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, R. P. China 2 Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-77, Japan  Sn+ ions were implanted into n-type lead telluride with doses of 6*10**16 and 1*10**17 ions/cm2 at an energy of 200 KeV. The thermoelectric properties of temperature dependence of the implanted and the unimplanted samples after annealing were investigated. Thermoelectric figure of merit was calculated using the measured data. It has been found that Sn+ ion implantation can form a two layered FGM with stepwise carrier concentration, and modify the thermoelectric properties of n-type PbTe. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 717-724 Sn+イオン注入多結晶性テルル化鉛の電気的特性と構造 Electrical Properties and Structure of Sn+ Ion Implantation Polycrystalline Lead Telluride L. Zhang 1, Q. Shen 1, G. Wang 1, 陳立東2, R. Tu 2 and 平井敏雄 21 State Key Lab. of Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, R. P. China 2 　東北大学 金属材料研究所　980-8577 宮城県仙台市青葉区片平２丁目１－１ L. Zhang 1, Q. Shen 1, G. Wang 1, L. Chen 2, R. Tu 2 and T. Hirai 21 State Key Lab. of Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, P. R. China 2 Institute for Materials Research, Tohoku University, Sendai 980-77, Japan  Polycrystalline PbTe samples have been implanted by Sn+ ion at 200KeV with doses of 6*10**16 and 1*10**17 ions/cm2 in order to create a modified Pb1-xSnxTe layers with gradation of carrier concentration. The electrical conductivity, Hall coefficient and thermoelectric power measurements have been carried out at 300K on the implanted samples. The effect of Sn+ ion implantation on structure of PbTe has been investigated using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM) and X-ray Photoelectron Spectroscopy (XPS). The results indicate the possible presence of Pb1-xSnxTe (x=0.2-0.25) phase during the ion-implantation processes. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 725-730 Bi2Te3-素地化合物の障壁と共鳴散乱 Barrier and Resonance Scattering of Bi2Te3-Based Compounds M. K. Zhitinskaya 1, S. A. Nemov 1, T. E. Svechnikova 2 and L. D. Ivanova 21 State Technical University, 29 Polytechnichaskaya, RU-1 95251 St.-Petersburg, Russia E-Mail: marina@nym.spb.ru, Phone: +7 (812) 513-3256, Fax: +7 (812) 327-4613 2 A. A. Baikov Institute of Metallurgy of Russian Academy of Science, RU-117334 Moscow, Russia E-Mail: ivanova@lesr.imet.ac.ru, Phone: +7 (095) 135-9611, Fax: +7 (095) 135-8680 M. K. Zhitinskaya 1, S. A. Nemov 1, T. E. Svechnikova 2 and L. D. Ivanova 21 State Technical University, 29 Polytechnichaskaya, RU-1 95251 St.-Petersburg, Russia E-Mail: marina@nym.spb.ru, Phone: +7 (812) 513-3256, Fax: +7 (812) 327-4613 2 A. A. Baikov Institute of Metallurgy of Russian Academy of Science, RU-117334 Moscow, Russia E-Mail: ivanova@lesr.imet.ac.ru, Phone: +7 (095) 135-9611, Fax: +7 (095) 135-8680  At the present time the elaboration of thermoelectrical (TE) materials with improved properties by using metalloceramic technology has attracted considerable attention. The electrophysical properties of the TE materials change due to selective scattering of charge carriers on barriers formed on intercrystalline's boundaries.       The potential barriers could be approached by different ways.       One way is to decrease the grain size. The electrophysical properties of TE materials based on Bi2Te3, manufactured by the different powder methods (metalloceramic, extruded) and having different grain size are compared with properties of single crystals grown by Czohralsky method.       Another way is to find and to use the impurity creating resonance levels. The influence of doping with Sn atoms on electrophysical properties of Bi2Te3 is investigated also. It is assumed that its unusual properties can be explained by the fact that Sn are situated not only on Te1 or Te2 lattice position but are in interplane positions between quintets of Bi2Te3 and create the resonant level. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 731-735 FGMへのAgSbTe2の適応性 Adaptability of AgSbTe2 to FGM 米田征司 1、太田英二 1、篠原嘉一 2、木村隆 2、西田勲夫 2、海部宏昌 31　慶応義塾大学 　神奈川県　2　金属材料技術研究所　茨城県3　東京都立大学　東京都 S. Yoneda 1, E. Ohta 1, Y. Shinohara 2, T. Kimura 2, I. A. Nishida 2 and H. T. Kaibe 31 Keio University, Kanagawa, Japan 2 National Research Institute for Metals, Ibaraki, Japan 3 Tokyo Metropolitan University, Tokyo, Japan  Thermoelectric properties of the unidirectionally grown p-type AgSbTe2 and Ag0.208Sb0.275Te0.517 boules have been evaluated to investigate adaptability of these materials system to functionally graded thermoelectric materials (FGMs). The AgSbTe2 boule contained even more Ag2Te precipitates than the Ag0.208Sb0.275Te0.517. Thermoelectric properties for these boules showed the different temperature dependence, which were strongly affected by the transformation at 418 K and also 633 K. The Ag2Te boule grown under similar condition as AgSbTe2 and Ag0.208Sb0.275Te0.517 is an n-type conductor. Thermoelectricmotive force E0 of the p-type AgSbTe2 boule is decreased by n-type Ag2Te precipitates. Pmax of Ag0.208Sb0.275Te0.517 boule were four times as large as that of AgSbTe2 at temperature difference (delta)T=350 K, and also equaled that of the segmented Pb1-xSnxTe compound newly developed. High temperature phase of AgSbTe2 above 633 K revealed its high potential of power generation. It is concluded that there is possibility of developing more superior thermoelectric materials by controlling structure and composition. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 736-741 傾斜機能構造を伴う多孔性熱電材料 Porous Thermoelectric Materials with Functionally Graded Structures 安田秀幸、大中逸雄、梶浦英亮、矢野哲也大阪大学　知能・機能創成工学　565-0871　大阪府 H. Yasuda, I. Ohnaka, H. Kaziura and T. YanoDepartment of Adaptive Machine Systems, Osaka University, Osaka 565-0871, Japan  Porous thermoelectric devices utilizing heat convection by gas flow through the porous device has been proposed. Functionally gradation of thermoelectric and porous properties can satisfy with the requirment for the porous device. However, because many thermoelectric materials such as FeSi2, (Bi,Sb)2Te3 and PbTe are generally brittle, development of processing of porous thermoelectric devices has been hoped. A novel hot press method was developed to form porous medium of the brittle FeSi2, (Bi,Sb)2Te3 and PbTe materials. In this method, porosity ratio was controlled upto 35% and permeability in order of 10**-9 or 10**-10 m2, and functional gradation of porous properties can be achieve. By this method, the functionally graded porous devices was also formed for FeSi2/(Bi,Sb)2Te3 and (Bi,Sb)2Te3/PbTe systems. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 742-747 MA複合粉末のプラズマ溶射による傾斜機能熱電コーティングの製造 Fabrication of Functionally Graded Thermoelectric Coatings by Plasma Spraying of Mechanically-Alloyed Composite Powders 福本昌宏、時本雄次、三河克明、田中康徳豊橋技術科学大学　生産システム工学系　441-8580　愛知県豊橋市天伯町字雲雀ケ丘１－１ M. Fukumoto, Y. Tokimoto, H. Mikawa and Y. TanakaDepartment of Production Systems Engineering, Toyohashi University of Technology, 1-1, Tempaku-cho, Toyohashi, Aichi 441-8580, Japan  Functionally graded structure is regarded as the effective system for thermoelectric conversion (TEC) material. In this study, homogeneously mixed metal/metal composite powders made by mechanical alloying (MA) were applied to plasma spraying to obtain the intermetallic TEC coatings, and the process conditions for getting the high performance TEC coatings were investigated. Consequently, optimum conditions of mechanical alloying, plasma spraying and post heat treatment to get the appropriate thermoelectric phases for each material system were empirically decided. As the fundamental research for the functionally graded TEC coating, the joint type Si-Ge coating with different dopant compositions was applied to be fabricated and the thermoelectric property of the joint was evaluated. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 748-753 熱電装置のためのFGMsの熱溶射 Thermal Spraying of FGMs for Thermoelectric Devices E. Lugscheider and G. LangerMaterials Science Institute, Aachen University of Technology, Julicher Strasse 344a, DE-52070 Aachen, Germany E. Lugscheider and G. LangerMaterials Science Institute, Aachen University of Technology, Julicher Strasse 344a, DE-52070 Aachen, Germany  Previous investigations have shown that it is possible to manufacture thermoelectric (TE) materials by thermal spraying without losing their TE-properties. The grading of different TE-materials can rise the conversion efficiency of complete TE-generators significantly. If it is possible to produce thick functionally graded TE-structures by Thermal Spraying this technology has the potential to produce complete TE-generator units. This paper describes one simple method to produce graded structures of materials with similar density and melting points by Thermal Spraying using steel as model material and Iron Disilicide as TE-material graded over a thickness of 10mm. The quality of the different gradients has been made visible by light microscopy (LM) and EDX-analysis. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 754-759 傾斜熱電素子の実条件テスト Real Condition Test of Graded Thermoelectric Elements E. Muller, J. U. Bruch and J. SchilzGerman Aerospace Center-DLR, Institute of Materials Research, DE-51170 Koln, Germany E. Muller, J. U. Bruch and J. SchilzGerman Aerospace Center-DLR, Institute of Materials Research, DE-51170 Koln, Germany  A test facility for graded thermoelectric elements has been developed, which simulates application relevant thermal conditions. The typical case of thermogenerator (TEG) use implies a difference of several hundred degrees between its hot and cold side. Therefore, the TEG device behaviour is essentially influenced by its transport properties' temperature dependence.       In a vacuum chamber, reference blocks for heat flow determination are serially connected to the generator sample. Special solutions have been found to prevent disturbance of the heat flux distribution due to radiation. Ductile and liquid metal interlayers have been used to obtain good electrical and thermal coupling between sample and reference.       A fine tuning of very low resistive loads is required to study the efficiency and electrical power output for arbitrary temperature conditions. For this purpose, a computer controllable electrical load with high accuracy has been developed. The operation of this new set-up has been tested. This includes the examination of segmented thermoelectric (TE) elements composed of FeSi2 with different dopings. The thermo-voltage, resistance, thermal conductance and effective figure of merit Z have been measured.       The method allows to compare the properties of real graded systems with the TE material properties to estimate the influence of material contacts. An experimental valuation of the theoretically predicted operating conditions for maximum efficiency and maximum power output, respectively, is enabled. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 760-765 W/TiB2/SiGeおよびW/MoSi2/SiGeシステム中の熱電変換ユニットの一段階焼結 One-Step Sintering of Thermoelectric Conversion Units in the W/TiB2/SiGe and W/MoSi2/SiGe Systems 林君山1、宮本欽生1、柴田賢朗2、廣田　健2、山口修21　大阪大学接合科学研究所　大阪府2　同志社大学　工学部　京都府 J.S. Lin 1, Y. Miyamoto 1, K. Shibata 2, K. Hirota 2 and O. Yamaguchi 21 Joining & Welding Research Institute, Osaka University, Osaka, Japan 2 Faculty of Engineering, Doshisha University, Kyoto, Japan  Dense thermoelectric conversion units in the systems of the W/TiB2/SiGe and W/MoSi2/SiGe were fabricated in one step by using glass encapsulation HIP. In order to relax the thermal residual stress and prohibit the chemical reaction between the W and SiGe, the electrode was designed as a graded structure through TiB2 and MoSi2 interlayers. The electrical resistivity, and their thermal stability were evaluated. The results showed that the SiGe kept the same electrical resistivity as its initial value (about 1.5-2.0x10**-3 (ohm)cm). In the zone of electrode, the electrical resistivity decreased to about 10**-4(ohm)cm. The measurements of electrical resistivity suggested that the combinations of the W/TiB2/SiGe for p-type, W/MoSi2/SiGe for n-type thermoelectric conversion units were suitable for obtaining optimum and thermally stable electrical resistivity proiles. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 766-773 銅/タングステン勾配の粉末冶金製造と特性 Powder Metallurgical Processing and Properties of Copper/Tungsten Gradients U. Birth, M. Joensson and B. KiebackUniversity of Technology Dresden, Germany U. Birth, M. Joensson and B. KiebackUniversity of Technology Dresden, Germany  A graded composition of Copper and Tungsten offers the chance for the application of materials which combines on one side high thermal and mechanical resistance and on the other side high thermal and electrical conductivity. W/Cu gradient materials were produced by Centrifugal Powder Forming. Thereby the possibility of mixing variations for the development of gradient materials with different concentration limits, different exponents of gradient function and also for pore structure gradients can be used. Because of the difference in the sintering behaviour the consolidation has to be adapted to the concentration areas. With the aim to produce dense sintering bodies liquid phase sintering, activation of sintering by additives and the HIP process as well as the infiltration of porous Tungsten parts with porosity gradient were used. Dilatometry, the investigation of microstructure and neutron diffraction measurements enable the characterisation of density and material composition development, thermal expansion and thermal stresses.      The advantages and limits of the powder technology will be discussed in connection with the material properties. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 774-781 熱イオンエネルギーコンバーターのRe/W/MoおよびIr/W/Taエミッタ‐ Re/W/Mo and Ir/W/Ta Graded-Structure Emitters of Thermionic Energy Converter 加藤昌宏、岡本　謙一、堀田秀和、五十嵐廉東京タングステン株式会社　931-8543　富山県富山市岩瀬古志町２ M. Katoh, K. Okamoto, H. Horita and T. IgarashiTokyo Tungsten Co., Ltd., 2 Iwasekoshi-machi, Toyama-shi, Toyama 931-8543, Japan  Rhenium and iridium exhibit excellent thermionic electron emission characteristics in a cesium plasma converter, owing to their low work function in cesium vapor. The maximum power density and output characteristics of an emitter surface with iridium or rhenium layers were simulated, and the surface was expected to be improved compared with other refractory metals such as polycrystalline rhenium, tungsten and molybdenum. The rhenium/tungsten/molybdenum graded structure was fabricated by chemical vapor deposition. In order to improve the thermal stability of the rhenium layer at elevated temperatures, tungsten layer was inserted between the rhenium layer and the molybdenum substrate to form graded-composition interfaces. The iridium/tungsten/ tantalum graded-structure emitter has been successfully produced by annealing at high temperature following hot isostatic pressing. When the tantalum component reacted with the iridium emitter, a 2226 K low-melting-point phase appeared. A three-layer structure with tungsten as the intermediate layer was selected to enhance the thermal stability of the emitter. The procedure of an elastic thermal stress analysis of functionally graded emitters by the axisymmetric finite-element method is presented. Thermal stresses are reduced to form graded-composition interfaces of rhenium/tungsten/molybdenum and iridium/tungsten/tantalum systems in the simulated model. The maximum power of a thermionic energy converter of a rhenium/tungsten/molybdenum emitter is 7.9 W/cm2 and that of an iridium/tungsten/tantalum emitter is 2.6 W/cm2. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 782-787 電気化学的に製造した傾斜タングステン/銅複合材料の特性評価 Characterisation of Electrochemically Processed Graded Tungsten/Copper Composites R. Jedamzik, A. Neubrand and J. RodelDarmstadt University of Technology, Department of Materials Science, Petersenstr. 23, DE-64287 Darmstadt, Germany R. Jedamzik, A. Neubrand and J. RodelDarmstadt University of Technology, Department of Materials Science, Petersenstr. 23, DE-64287 Darmstadt, Germany  Tungsten/copper gradient materials have been produced by electrochemical treatment of sintered tungsten preforms and subsequent infiltration with copper in a second production step. The characteristics of the gradient have been adjusted by varying the experimental parameters current density, electrolyte conductivity, electrolysis time and initial porosity. The profile of the gradient was successfully predicted with a numerical model. The position dependent Young's modulus and thermal expansion coefficient of very thin bars cut perpendicular to the gradient was determined. Rules of mixture provide good predictions of measured values and show the importance of processing for thermomechanical properties. English Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials,held in New Town Hall,Dresden.Germany,october 26-29,1998 Functionally Graded Materials 1998Proceedings of the 5th International symposium on Functionally Graded Materials 6 1998-12-31 788-793 コーティングしたNi/YSZによる高温固体電解質型燃料電池(SOFC)陽極の改良された触媒特性 Improved Catalytic Properties of Solid Oxide Fuel Cell (SOFC) Anodes by Coated Ni/YSZ U. Flesch, J. Meusinger, A. Naoumidis and D. StoverInstitut fur Werkstoffe und Verfahren der Energietechnik (IWV), Forschungszentrum Julich GmbH (FZJ), DE-52425 Julich, Germany U. Flesch, J. Meusinger, A. Naoumidis and D. StoverInstitut fur Werkstoffe und Verfahren der Energietechnik (IWV), Forschungszentrum Julich GmbH (FZJ), DE-52425 Julich, Germany  The endothermal steam reforming reaction of methane within the anode chamber of solid oxide fuel cell (SOFC) stack (internal reforming) is favorably applied to reduce cost and improve the thermal balance within the stack. This reaction, catalysed by the Ni/YSZ anode material (substrate), is very fast and influences the temperature distribution in the stack considerably. In the fuel inlet area of the anode strong cooling can occur leading to large temperature gradients to the anode substrate. Therefore, the catalytic activity for reforming the Ni/YSZ has to be decreased at the top layer of the anode material which is in contact with the fuel gas mixture. On the other hand, at the interface between anode and electrolyte a high electrochemical activity is necessary. Hence, the anode has to be designed from a functionally graded material. To reduce the catalytic activity, YSZ coating was carried out without decreasing the gas permeability and the electrical conductivity of the substrate. Various sols prepared from precursors Y(NO3)3 *6 H2O and Zr(OC3H7)4 were applied to the Ni/YSZ in order to verify the influence of the parameters mentioned above. English