# Fileset [related-papers.xlsx](https://mdr.nims.go.jp/filesets/56f5aca6-674f-4bd1-a29c-3f2f69464324/download) ## Creator National Institute for Materials Science ## Rights ## Other metadata [Related papers](https://mdr.nims.go.jp/datasets/47bed147-fdab-4b23-b3a7-fbde51d5aade) ## Fulltext Sheet1 BookTitle_j BookTitle_e Volume/Issue Issueddate Page Title_j Title_e AuthorList_j AuthorList_e Abstract Language 日本機械学会論文集(A編), 58（1992.12） (Publication) Proceedings of Japan Society of Mechanical Engineers vol.A, 58（1992.12） 1992-12-01 2472-2477 遠心力を利用した傾斜機能材料の組成制御 Control of functionall graded material composition by centrifugal force 渡辺義見，福井泰好，中西賢二，武田吉男，山中昇 Yoshimi Wantanabe, Yasuyoshi Fukui, Kenji Nakanishi, Yoshio Takeda, Noboru Yamanaka The formation process of a gradation in composition under a centrifugal force in functionally graded material (FGM) fabrication has been studied. The motion of ceramic particles in the viscous liquid, which corresponds to liquid metal, was analyzed by numerical calculation. The gradations of ceramic particle distributions in viscous liquid are visualized with the aid of computer graphics. These results are in good agreement with results of experiments which use the corundum/plaster model, including the size effect. Thus, the method of simulation presented in this study can properly estimate the gradation in composition. From the results of simulation and experiment using the model, it is also found that precise control of composition can be achieved by simultaneously using particles of different grain sizes. Japanese J. Mater. Sci. Letters, 12（1993.3） (Publication) J. Mater. Sci. Letters, 12（1993.3） 1993-03-01 326-328 マルテンサイト変態による変形で製造された磁気的傾斜機能材料 A Magnetic Functionally Graded Material Manufactured with Deformation Induced Martensitic Transformation 渡辺義見，中村祐三，福井泰好，中西賢二 Y. Watanabe, Y. Nakamura, Y. Fukui, K. Nakanishi The aims of the authors' study were to manufacture the magnetic FGM by applying gradually inhomogeneous deformation to SUS304 austenitic stainless steel (Fe-18Cr-8Ni) and to examine the relationship between the saturation magnetization and the local strain. It is manifested that a magnetic FGM can be easily manufactured using a tensile piece of austenitic stainless steel with a gradient of cross-sectional area. Since the amount of deformation-induced martensite depends on the local strain, it is possible to obtain the desired magnetic FGMs when the virgin materials are processed to have the suitable local strains for the desired functions English 日本機械学会論文集(A編), 59（2003.4） (Publication) Proceedings of Japan Society of Mechanical Engineers vol.A, 59（2003.4） 2003-04-01 1138-1143 SUS304ステンレス鋼のマルテンサイト変態を利用した磁気的傾斜機能材料 SUS304 Stainless steel-based magnetic functionally graded materials using martensitic transformation technique 渡辺義見，中村祐三，福井泰好，中西賢二 Y. Watanabe, Y. Nakamura, Y. Fukui, K. Nakanishi Wedge-shaped plates of SUS304 austenitic stainless steel with inclination angles of 1 and 3 degrees were deformed in tension at room temperature. A less slanted specimen showed strain distribution graded nearly linearly along the tensile axis, which provided a good gradient of magnetic property resulting from the formation of ferro-magnetic α' martensite. A specimen with an inclination angle of 3 degrees, however, exhibited more inhomogeneity of plastic deformation which is unsuitable for the magnetic-FGM. A theoretical evaluation for the distributions of strain and saturation magnetization was conducted using a simple model, which turned out to be in good accordance with the experimental results. Other processing methods and engineering applications of the magnetic-FGM were also discussed. Japanese Metall. Mater. Trans.A, 27A （1996.12） (Publication) Metall. Mater. Trans.A, 27A （1996.12） 1996-12-01 4145-4151 Duralcan型Al-SiC FGMの厚肉リングにおける熱残留応力の解析 Analysis of Thermal Residual Stress in a Thick Walled Ring of Duralcan-Base Al-SiC Functionally Graded Material 福井泰好，渡辺義見 Y. Fukui, Y. Watanabe A ring cutting test and an elastic theory were applied to evaluate the macroscopic residual stress in a thick-walled ring made of Al - SiC functionally graded material (FGM). FGM ring specimens with outer diameter 90 mm, radial thickness 8.4 ~ 10 mm, and width 30 mm were fabricated by the centrifugal casting method from an ingot of Duralcan F3D.20S of Al - 20 vol% SiC master composite. Due to a difference in centrifugal forces of SiC particles and of molten aluminum alloy, the rings had a graded composition of SiC particles in radial direction. The volume fractions of SiC particles in each ring specimen varied in the range of 0 ~ 43 vol% from inner to outer surface of the ring depending on the applied mold spin speed. A ring diametral compression test was performed to validate an analytical formula based on the curved beam theory which can account for the graded properties of the material. A excellent agreement between the theory and the experiment was found. The residual stress was found to be generated by a cooling of DT = 140 K, which was from half the me lting point corresponding stress free condition to the ambient temperature. The hoop residual stresses in the FGM ring varied in the range of -50 ~ +35 MPa and from tension at inner to compression at outer surface because of the graded composition. With an increase in wall-thickness and/or composition gradation, the residual stresses were found to increase. English Z. Metallkd., 88（1997.9） (Publication) Z. Metallkd., 88（1997.9） 1997-09-01 717-721 AlのAl3Ti板の配向 Orientation of Al3Ti Platelets in Al 渡辺義見，山中昇，福井泰好 Y. Watanabe, N. Yamanaka, Y. Fukui Al-Al3Ti functionally graded materials (FGMs) were manufactured by the centrifugal method with a commercial ingot of Al-5 mass% Ti master alloy. The alloy was melted at a liquid/solid coexisting temperature, at which Al3Ti remains as a solid, and then it was cast into a thick-walled ring. It was found that the Al-Al3Ti functionally graded material can be successfully fabricated by the centrifugal method. It was also found that the volume fraction of the Al3Ti can be increased by repetition of the centrifugal method. Since the shape of Al3Ti particles in a commercial alloy ingot is that of a platelet, the Al3Ti particles are arranged with their platelet planes nearly perpendicular to the radial direction. The orientation effects become stronger when the G number becomes larger. Although the final centrifugal casting was conducted under a very large centrifugal force for the specimen cast three times, the orientation effects were weaker than those in the specimen cast one time. From these observations, it is concluded that the origin of orientation of Al3Ti platelets can be attributed to the angular velocity gradient of the melt along the radial direction produced by the difference in the viscosity. English Composites Part A, 29A（1998.6） (Publication) Composites Part A, 29A（1998.6） 1998-06-01 595-601 遠心分離法で作製した金属ーセラミック傾斜機能材料における組成傾斜制御 Control of Composition Gradient in a Metal-Ceramic Functionally Graded Material Manufactured by the Centrifugal Method 渡辺義見，山中昇，福井泰好 Y. Watanabe, N. Yamanaka, Y. Fukui The motion of ceramic particles in a molten metal of a viscous liquid under a centrifugal force is numerically modeled to study the formation process of composition gradients. The simulated results are in good agreement with those of experiments that used a plaster-corundum model functionally graded material (FGM). It is found that greater gradients are obtained in cases of thinner thickness, greater applied centrifugal forces and smaller mesh size particles. In addition, the processing of mixed mesh size particles is examined. We conclude that the use of a mixture of particle sizes is particularly useful to control the composition of metal-ceramic FGMs manufactured by the centrifugal method. English Mater. Trans., JIM, 40（1999.9） (Publication) Mater. Trans., JIM, 40（1999.9） 1999-09-01 961-966 くさび形状304ステンレス鋼の圧延変形による磁気的傾斜材料の作製 Fabrication of Magnetically Graded Material by Rolling Deformation of Wedge-shaped 304 Stainless Steel 渡辺義見，S. H. Kang, J. W. Chan and J. W. Morris, Jr. Y. Watanabe, S. H. Kang, J. W. Chan and J. W. Morris, Jr. ローレンスバークレー国立研究所ローレンスバークレー国立研究所ローレンスバークレー国立研究所 This paper reports a technique that fabricates a magnetically graded material in which the saturation magnetization varies linearly as a function of distance. An initially wedge-shaped 304 stainless steel was rolled into a rectangular cross section. The saturation magnetization curve as a function of rolling ratio has a positive curvature. Since the rolling ratio distribution showed a negative curvature, it was possible to achieve a nearly linear magnetic gradient along the specimen. Furthermore, it was found that the hardness also varied gradually in the deformed specimen, suggesting that the technique presented in this work can fabricate a functionally graded material not only in magnetic properties but also in mechanical properties. English Metall. Mater. Trans.A, 30A （1999.12） (Publication) Metall. Mater. Trans.A, 30A （1999.12） 1999-12-01 3253-3261 遠心力法で製造されたAl-Al3Ti複合材の摩耗挙動 Wear Behavior of Al-Al3Ti Composite Manufactured by a Centrifugal Method 渡辺義見，山中昇，福井泰好 Y. Watanabe, N. Yamanaka, Y. Fukui The purpose of the present study was to develop a wear-resistant, light Al-Al3Ti composite material. An Al-Al3Ti composite specimen was machined from a thick-walled tube of Al-Al3Ti functionally graded material (FGM) manufactured by the centrifugal method from a commercial ingot of Al-5 mass pct Ti master alloy. The alloy was heated to a temperature where solid Al3Ti particles resided in a liquid Al matrix, and then the centrifugal method was carried out. Al3Ti particles in a commercial alloy ingot exist as platelets, and this shape was maintained through the casting. Three kinds of wear specimens were prepared, taking into account the morphology of the Al3Ti particles in the thick walled FGM tube; the Al3Ti particles were arranged with their platelet planes nearly normal to the radial direction as a result of the applied centrifugal force. The wear resistance of the Al-Al3Ti composite was significantly higher than that of pure Al. Wear-resistance anisotropy and dissolution of the Al3Ti into the Al matrix at the near-surface region, around 100 μ m in depth, were also observed. The mechanism of the supersaturated-layer formation and the origin of the anisotropic wear resistance are discussed. English Aluminum Trans., 2, No. 2（2000.6） (Publication) Aluminum Trans., 2, No. 2（2000.6） 2000-06-01 195-209 遠心力法によるAl傾斜機能材料の作製 Fabrication of Functionally- Graded Aluminum Materials by the Centrifugal Method 渡辺義見，福井泰好 Y. Watanabe, Y. Fukui Functionally-graded materials (FGMs) are a new class of materials in which the composition and/or the microstructure varies in one specific direction. One of the promising methods for the fabrication of FGM is the centrifugal method, which is an application of the centrifugal casting technique. In this method, a centrifugal force applied to the mixture of molten metal and dispersed material, such as ceramics powders or intermetallic compounds, leads to the formation of the desired gradation. The composition gradient is then achieved mainly due to the applied centrifugal force and the difference in densities of the molten metal and particles. The centrifugal method has the advantage of a possible application to the mass production of small and large FGM specimens. In the review, we first describe the fabrication method and microstructures of aluminum based FGMs and then discuss some recent results about the physical properties of FGMs fabricated by the centrifugal method. The physical properties of aluminum-based FGMs were also investigated using relatively large samples. English Mater. Trans., JIM, 41（2000.10） (Publication) Mater. Trans., JIM, 41（2000.10） 2000-10-01 1322-1328 遠心鋳造されたAl-Al3Ti傾斜機能材料における転位構造の周期的変形および発達 Cyclic Deformation and Development of Dislocation Structures in a Centrifugally Cast Al-Al3Ti of Functionally Graded Material 山下健，渡辺千尋，熊井真次，加藤雅治，佐藤彰一，渡辺義見 K. Yamashita, C. Watanabe, S. Kumai, M. Kato, A. Sato, Y. Watanabe長岡技科大金沢大学東京工業大学東京工業大学東京工業大学 An Al-Al3Ti composite has been prepared to contain a large volume fraction of D022 ordered Al3Ti phase on one side and a smaller volume fraction on the other side by a functional grading process. The cyclic stress-strain curves obtained by strain control tests are compared with the available data on Al to delineate the effects of the Al3Ti plates distributed with concentration gradient. Examination of the crack nucleation and growth by a replica method has revealed that introduction of the non-deformable Al3Ti accelerates crack nucleation but concurrently hinders the spontaneous propagation in the cyclic tests. Observation of the final structure by HVEM has further revealed that presence of the non-deformable Al3Ti induces non-uniform distribution of dislocations near the Al3Ti plate, causing build-up of stress inhomogeneity, especially on the Al3Ti rich side. On the basis of these observations, utility of the FGM specimens is discussed with a particular interest in the lifetime prediction under cyclic loading. English Metall. Mater. Trans. A, 31A（2000.12） (Publication) Metall. Mater. Trans. A, 31A（2000.12） 2000-12-01 2627-2636 共晶融点よりも高い温度でのAl-Al3Ni FGMのニアネットシェイプ形成 Near Net Shape Forming of Al-Al3Ni FGM over Eutectic Melting Temperature 福井泰好，岡田裕，熊澤典良，渡辺義見 Y. Fukui, H. Okada鹿児島大学, N. Kumazawa, Y. Watanabe A possibility to make near-net-shape functionally graded material (FGM) products has been examined. The FGM billets having a graded volume fraction of Al3Ni in thickness direction were machined from an Al-Al3Ni FGM thick-walled tube manufactured by a vacuum centrifugal method. Billets, which were set in the container for the backward extruding, were heated to 650 ｰC to 680 ｰC, at which temperature the FGM becomes a mixture of molten aluminum eutectic and solid intermetallics. Then, billets were extruded successfully to FGM cups by a semisolid forming, except at 650 ｰC. Residual bulky Al3Ni particles are found at higher temperature. Thus, an optimum operation temperature is found to be around 660 ｰC, because bulky Al3Ni particles transform to fine spheroidal or fibrous shape after the forming. The volume fraction of intermetallics at the bottom region of the cup was condensed more than 60 vol pct in a proper billet setting. English Intermetallics, 9（2001.2） (Publication) Intermetallics, 9（2001.2） 2001-02-01 33-43 遠心力法によるハイブリッドAl-(Al3Ti+Al3Ni)FGMsの構造および摩耗抵抗 Microstructures and Wear Resistances of Hybrid Al -(Al3Ti + Al3Ni) FGMs by Centrifugal Method 渡辺義見，中村立 Y. Watanabe, T. Nakamura 信州大学 The Al based functionally graded materials (FGMs), reinforced by a hybrid of Al3Ti platelets and Al3Ni granular particles, were fabricated by the centrifugal method with both ingots of commercial Al-5mass%Ti and Al-20mass%Ni master alloys. The ratios of Al-Ti and Al-Ni alloys were 3:1, 1:1 and 1:3 (in mass), and the applied G numbers are 30, 50 and 80. The microstructures of hybrid Al-(Al3Ti+Al3Ni) FGMs were observed with an optical microscope (OM) and a scanning electron microscope (SEM). Since the gradient distributions in orientation of Al3Ti platelets and in particle size of Al3Ni primary crystal particle were expected to be formed in the fabricated hybrid Al-(Al3Ti+Al3Ni) FGMs, detail observations of the orientation of Al3Ti platelets and the size of Al3Ni granular particles were performed. The wear resistance of the FGMs was measured by an Okoshi-type wear machine. Based on the experimental results, the advantages of hybrid Al-(Al3Ti+Al3Ni) FGMs were discussed. English J. Appl. Phys., 89（2001.2） (Publication) J. Appl. Phys., 89（2001.2） 2001-02-01 1977-1982 高Tc超伝導量子干渉計(SQUID)によるステンレス鋼内の磁気的傾斜の観察 Observation of Magnetic Gradients in Stainless Steel with a High-Tc Superconducting Quantum Interference Device Microscope 渡辺義見，S. H. Kang, J. W. Chan, J. W. Morris, Jr., T. J. Shaw, J. Clarke Y. Watanabe, S. H. Kang, J. W. Chan, J. W. Morris, Jr., T. J. Shaw, J. Clarkeローレンスバークレー国立研究所ローレンスバークレー国立研究所カリフォルニア大学バークレー校カリフォルニア大学バークレー校 Superconducting quantum interference device (SQUID) microscopes may serve as useful nondestructive evaluation (NDE) tools since they can precisely measure the local magnetic field variation that can be related to the characteristics of ferromagnetic materials. To demonstrate this, we have studied magnetic functionally graded materials (FGMs) in the Fe-Cr-Ni alloy system using a high-transition-temperature (HTc) SQUID microscope. The FGMs were either fabricated by inhomogeneous mechanical deformation or by heat treatment in a temperature gradient. The magnetic properties of these materials were measured using the vibrating sample magnetometer technique along the deformation or the temperature gradients. The results from this technique and the microstructural properties from optical imaging are discussed in conjunction with the magnetic field images obtained from the SQUID microscope. By exploring the results, the feasibility and benefit of utilizing SQUID microscopy as a NDE tool are discussed. English Z. Metallkd., 92（2001.2） (Publication) Z. Metallkd., 92（2001.2） 2001-03-01 53-57 金属系FGMの組織傾斜を評価するための微小硬度測定 Micro-hardness Measurements to Evaluate Composition Gradient by in Metal-Based Functionally Graded Materials 渡辺義見，山中昇，清宮義博，福井泰好 Y. Watanabe, N. Yamanaka, Y. Oya-Seimiya明星大学, Y. Fukui Micro-Vickers hardness measurement is used to determine the composition of functionally graded materials (FGMs). Materials used in the present study are Al-SiC, Al-Shirasu and Al-Al3Ni FGMs, which are fabricated by a centrifugal method. The micro-hardness of the aluminum matrix for Al-SiC FGM markedly increases as the volume fraction of SiC particles increase. However, the tendency is not so clear in the cases of Al-Shirasu and Al-Al3Ni FGMs. Plastic strain energy due to thermal misfits between the matrix and dipersed particles is calculated based on an elasto-plastic analysis by applying a shell theory after Lee et al. The hardness is correlated theoretically with the composition gradient through the mean plastic strain energy (responsible for dislocation density). It is concluded that the composition gradient of metal-based FGMs can be determined from micro-hardness measurements. English Acta Mater., 49（2001.3） (Publication) Acta Mater., 49（2001.3） 2001-03-01 775-783 遠心鋳造法により作製されたAl基FGMsのAl3Ti小板の三次元配向の評価 Evaluation of Three-Dimensional Orientation of Al3Ti Platelet in Al-based Functionally Graded Materials Fabricated by a Centrifugal Casting Technique 渡辺義見，江竜寛之，松浦清隆 Y. Watanabe, H. Eryu, K. Matsuura Al-Al3Ti functionally graded materials (FGMs) are fabricated by a centrifugal casting technique. The Al3Ti particle morphology is observed along three orthogonal planes, i.e. perpendicular to the rotation axis (OP1), perpendicular to the rotation direction (OP2), and perpendicular to the radial direction (the centrifugal force direction) (OP3). The Al3Ti particles are platelet in morphology and their planes are oriented nearly perpendicular to the radial direction. It is found that the orientation of Al3Ti platelets was distributed in the Al-Al3Ti FGMs in a gradually graded manner as well as the volume fraction of Al3Ti platelets. Namely, a larger volume fraction of Al3Ti platelets and a greater orientation of them are observed in the outer region of the ring. Moreover, there is a three-dimensional correlation in the orientation of Al3Ti platelets. Based on geometrical considerations, the orientation of the platelets on one observation plane of the orthogonal planes can be estimated from measurements on a plane perpendicular to the radial direction. The estimated orientation distribution closely agrees with that experimentally observed. Since each Al3Ti platelet-particle has almost the same orientation angle on two different planes, the orientation profiles observed on OP1 are very similar to those along OP2. English Comp. Sci. and Tech., 62（2002.3） (Publication) Comp. Sci. and Tech., 62（2002.3） 2002-03-01 881-888 遠心力固相法で作製されたFGMの粒径分布 Particle Size Distributions of Functionally Graded Materials Fabricated by Centrifugal Solid-Particle Method 渡辺義見，川本明弘，松田公一 Y. Watanabe, A. Kawamoto, K. Matsuda信州大学、信州大学 The aim of this study is to examine the possibility of the gradual particle size distributions in the functionally graded material (FGM) fabricated by centrifugal solid-particle method. FGM tubes were fabricated from plaster/corundum model materials containing five different particle sizes. The particle size distributions were directly determined by the extraction of the particles from the plaster matrix. The results reveal that the larger particles are located in the outer part of the tube. It was also found that the above phenomenon is affected by the G number as well as the mean volume fraction of particles. The experimental results fit well with the Stokes' law. English Mater. Trans., 44（2003.12） (Publication) Mater. Trans., 44（2003.12） 2003-12-01 2461-2467 AlおよびFe廃棄物の新しいリサイクルシステム---遠心力法で作製されたin-situ Al-Al3Fe傾斜機能材料 Novel Recycling System of Al and Fe Wastes - in-situ Al-Al3Fe Functionally Graded Material Manufactured by a Centrifugal Method 山際和久，渡辺義見，福井泰好，P. Kapranos K. Yamagiwa, Y. Watanabe, Y. Fukui and P. Kapranos東京工芸大学，信州大学，鹿児島大学，シェフィールド大学，イギリス In this study, the concept of novel recycling system using waste Al and Fe is described. Taking advantage of the fact that due to its cyclic usage, aluminum scrap unavoidably contains iron and steel wastes, an in-situ Al -Al3Fe functionally graded material (FGM) is planned to he fabricated. A centrifugal method is applied to a model master alloy, Al-10mass% Fe, obtained from virgin materials, the content of which is decided from the liquidus temperature. The resulting product is a thick-walled tube having a graded distribution of second phase particles in the Al matrix. It has been established that the shape of the particles varies depending on their position along the radial direction. The second phase is confirmed to he a stable Al3Fe intermetallic compound. Thin plates of Al- Al3Fe having homogeneously distributed AI3Fe particles, considering both the composition gradient and the particle morphology, were machined from the thick-walled Al- Al3Fe FGM tube and their mechanical properties measured. Based on the experimental observations, the potential and the advantages of the Al- Al3Fe alloy as a recyclable eco-FGM are discussed. English Mater. Trans., 45 （2004.4） (Publication) Mater. Trans., 45 （2004.4） 2004-04-01 1005-1009 硬度傾斜を持つポリ(L-乳酸）FGMの生物分解性 Biodegradability of Poly (L-lactic Acid) Functionally Graded Materials with Hardness Gradient 渡辺義見，岩元貴志，寺本彰，阿部康次，大越　豊 Y. Watanabe, T. Iwamoto, A. Teramoto, K. Abe and Y. Ohkoshi信州大学 The aim of this study is to develop a functionally graded material (FGM) of biodegradable poly (L-lactic acid) (PLLA) with a hardness gradient. For this purpose, the PLLA was extruded at elevated temperatures to introduce molecular orientation. Two types of extrusion, direct extrusion and equal channel angular (ECA) extrusion, were carried out. Heat treatment without extrusion was also carried out at 50ｰC, 60ｰC and 70ｰC. For the mechanical property characterization, the hardness distributions were investigated using a Vickers microhardness tester. Biodegradability of PLLA FGM was measured by evaluating the mass decreasing ratio after incubation in a physiological saline solution at 37ｰC. It was found that the PLLA FGMs with symmetric and asymmetric hardness gradients could be fabricated by direct extrusion and ECA extrusion at elevated temperature, respectively. Although in the initial state the mass of PLLA gradually increased with the softening of the FGM, it started to decrease after two weeks. English Metall. Mater. Trans. A., 35A（2004.4） (Publication) Metall. Mater. Trans. A., 35A（2004.4） 2004-04-01 1517-1524 液体アルミニウムおよび固体ニッケルから反応遠心鋳造法で作製されたニッケルアルミナイド金属間化合物／鉄鋼クラッドパイプ Nickel-aluminides/ Steel Clad Pipe Fabricated by Reactive Centrifugal Casting Method from Liquid Aluminum and Solid Nickel 渡辺義見，渡辺　暁，松浦清隆 Y. Watanabe, S. Watanabe, K. Matsuura信州大学信州大学北海道大学 A novel method to produce an aluminide/steel clad pipe has been proposed. The method is based on a combination of the self-propagating high-temperature synthesis (SHS) reaction and centrifugal casting, and is named the reactive centrifugal casting method. Nickel powder was placed on a rotating steel pipe, and aluminum liquid was poured into the steel pipe. The aluminum liquid and nickel powder exothermically reacted and produced a composite layer consisting of nickel aluminides on the inner surface of the steel pipe. The heat generated by the exothermic reaction melted the inner surface of the steel pipe and bonded the composite layer to the steel. It was found that increases in centrifugal force generated by rotating the steel pipe, the pouring temperature of the aluminum, and the preheating temperature of the nickel and steel remarkably promote the reaction between nickel and aluminum. In addition, the amounts of initial aluminum and nickel were found to play an important role in controlling the microstructure of the composite layer. Thus, the aluminide/steel clad pipe can be successfully fabricated by the proposed reactive centrifugal casting method. English Ironmaking & Steelmaking, 31 （2004.6） (Publication) Ironmaking & Steelmaking, 31 （2004.6） 2004-06-01 265-268 変形ステンレス鋼の不均質熱処理により作製された磁気的傾斜機能材料 Magnetically Graded Materials Fabricated by Inhomogeneous Heat Treatment of Deformed Stainless Steel 渡辺義見，百瀬 逸平 Y. Watanabe, I. Momose信州大学 The present work was undertaken with the objective of developing a magnetically graded material by a reverse martensitic transformation (RMT) technique in a controlled manner. Tensile deformed SUS type 304 stainless steel was annealed within a temperature gradient to introduce the reverse martensitic transformation inhomogeneously. The magnetisation distributions within specimens were evaluated using a vibrating sample magnetometer. It was found that the desired saturation magnetisation gradient was formed in the magnetically graded material fabricated by the RMT technique. Therefore, by controlling the thermal gradient in the furnace very carefully, it is possible to obtain a magnetically graded material with a suitable gradient of magnetisation using the _ reverse transformation in SUS 304 stainless steel. English ISIJ International, 44（2004.7） (Publication) ISIJ International, 44（2004.7） 2004-07-01 1258-1262 アルミ缶と切削屑の再利用による鉄アルミナイド金属間化合物の合成 Use of Recycled Steel Machining Chips and Aluminum Can Shreds for Synthesizing Iron Aluminide Intermetallic Alloys 松浦清隆，渡辺義見，平島康 K. Matsuura, Y. Watanabe, Y. Hirashima北海道大学信州大学徳島県立工業技術センター Some iron aluminide intermetallic alloys based on Fe3Al or FeAl have been synthesized from recycled raw materials of steel machining chips and aluminum can shreds. The former was an industrial waste made at a bearing case maker, and it had a spiral shape and a length less than 1 mm and contained 0.87 wt% C, 0.21 wt% Si, 1.53 wt% Cr with some other minor elements. The latter, on the other hand, was made by shredding used aluminum cans, and it had a flaky shape and a edge length of 2 to 3 mm and contained 2.3 wt% Mg, 0.36 wt% Fe, 0.88 wt% Mn with some other minor elements. When compacts of the steel and aluminum mixture were heated in a crucible in an argon atmosphere, they exothermically reacted and produced iron aluminide intermetallic alloys. For comparison, similar alloys were produced from pure iron and aluminum by melting them in the same heating apparatus. The bending strength, fracture toughness, Vickers hardness and wear resistance of the alloys synthesized from the recycled raw materials were more excellent than or similar to those of the alloys produced from pure iron and aluminum. English Sci. Eng. Comp. Mater., 11（2004.7） (Publication) Sci. Eng. Comp. Mater., 11（2004.7） 2004-07-01 185-199 遠心晶出法により作製されたAl-Al3Ni FGMsの粒径及び粒径分布の評価 Evaluation of Particle Size and Particle Shape Distributions in Al-Al3Ni FGMs Fabricated by a Centrifugal in-situ Method 渡辺義見，佐藤隆芳，松田公一，福井泰好 Y. Watanabe, R. Sato, K. Matsuda, Y. Fukui信州大学信州大学信州大学鹿児島大学 This paper reports concerning with the variation of particle size, particle shape and volume fraction distributions in Al-Al3Ni functionally graded materials (FGMs) fabricated by a centrifugal in-situ method. Eight specimens of Al-Al3Ni FGM were systematically selected for the experimental analysis. The microstructures of Al3Ni primary crystal particles were observed and then gradients of volume fraction of Al3Ni particles towards centrifugal force direction were measured. A detailed evaluation of particle size was done considering the area-equivalent diameter from cross-sectional area of each Al3Ni particle. Moreover, particle shape distributions were also conducted using functions concerning with both fractal dimension and circularity of particles. It is revealed that both particle size and particle shape of Al3Ni had graded distributions as well as volume fraction distributions within the FGMs. Those results were explained considering the effect of applied G number, Ni content in Al-Ni master alloy, cooling rate and stirring of melt. English Acta Mater., 53（2005.3） (Publication) Acta Mater., 53（2005.3） 2005-03-01 1631-1641 遠心晶出法により作製されたAl-Al2Cu傾斜機能材料における傾斜組成の形成メカニズム Formation Mechanism of Graded Composition in Al-Al2Cu Functionally Graded Materials Fabricated by a Centrifugal in-situ Method 渡辺義見，大池新 Y. Watanabe, S. Oike信州大学 To discuss the formation mechanism of the graded composition during the centrifugal in situ method, a detailed study of microstructures in the Al-Al2Cu FGMs fabricated by the centrifugal in situ method from various initial master ingots was carried out. It was found that FGMs can be fabricated by the centrifugal in situ method from not only hypoeutectic or hypereutectic alloys but also eutectic alloys. The particle sizes of the Al2Cu and Al primary crystals were dependent upon their locations in the ring thickness. Using the above experimental results, it has been concluded that the graded structure appearing in the eutectic specimen must be caused by the difference in the densities between Al and Cu in liquid state. English Mater. Trans., 46,（2005.5） (Publication) Mater. Trans., 46,（2005.5） 2005-05-01 944-949 ZK60A 合金から遠心力法により作製されたマグネシウム基傾斜機能材料 Magnesium-based Functionally Graded Material Fabricated by a Centrifugal Method from ZK60A Alloy 渡辺義見，佐藤隆芳，金 翼水，三浦誠司，三浦博己 Y. Watanabe, R. Sato, I-S Kim, S. Miura, H. Miura信州大学信州大学信州大学北海道大学電気通信大学 Magnesium based functionally graded material (FGM) was fabricated by a centrifugal method from ZK60A (Mg--5.5 mass%Zn--0.6 mass%Zr) alloy. The applied G numbers are 40, 80 and 120, where the G number is the centrifugal force in unit of gravity. The specimen shape was cylindrical with 18 mm in length. Microstructures of the fabricated FGM specimens were observed using SEM. Energy dispersive X-ray analysis was performed to study the chemical compositional gradients within the fabricated FGM specimens. It was found that concentration of Zr in the specimens increases toward the centrifugal force direction, while no or quite small chemical compositional gradient of MgZn2 appears. A hardness change along the centrifugal force direction was also found. The graded structures are caused by the difference in the formation mechanisms of compositional gradient during the centrifugal method between Zr and Zn. English Scripta Mater., 53, （2005.9） (Publication) Scripta Mater., 53, （2005.9） 2005-09-01 687-692 Al-Al3Ti傾斜機能材料の後方押し出し：Al3Ti粒子の体積分率傾斜及び異方性配向 Backward Extrusion of Al-Al3Ti Functionally Graded Material: Volume Fraction Gradient and Anisotropic Orientation of Al3Ti Particles P. D. Sequeira,渡辺義見，福井泰好 P. D. Sequeira, Yoshimi Watanabe and Yasuyoshi Fukui／University of Minho Al-Al3Ti FGM cups are manufactured through the semi-solid backward extrusion process. The billet is cut from an Al-Al3Ti FGM ring fabricated by a centrifugal solid-particle method. The master alloy is Al-5mass%Ti. Graded distribution of Al3Ti particles and a variation of the orientation of platelets are confirmed and discussed. English Mater. Sci. Eng. A, A416, 80-91 (2006.1) (Publication) Mater. Sci. Eng. A, A416, 80-91 (2006.1) 2006-01-01 80-91 半溶融点以上の温度で二アネットシェイプ成形されたAl-Al3Feエコ傾斜機能材料の特性化 Characteristic of Al-Al3Fe Eco-Functionally Graded Material through Near-Net-Shape Forming over Eutectic Melting Temperature 山際和久，渡辺義見，松田公一，福井泰好，Plato Kapranos Kazuhisa Yamagiwa, Yoshimi Watanabe, Koichi Matsuda, Yasuyoshi Fukui and Plato Kapranos東京工芸大学 With the concept of an eco-material in mind, this work looks into the possibility of manufacturing Al-Al3Fe functionally graded material (FGM) products by semi-solid extrusion. For this purpose, an Al-Al3Fe FGM thick-walled tube of 90 mm outer diameter × 90 mm long × 15 mm thickness was fabricated utilizing a vacuum centrifugal method. Al-Al3Fe FGM billets of 40 mm diameter × 12 mm thickness, with graded distribution from 0 to 40 vol% of coarse brittle Al3Fe particles in the thickness direction, were machined from the thick-walled FGM tube. The billets were pressed in the container at temperatures of 660, 670 and 680 deg.C, where Al alloy melt and solid Al3Fe particles co-existed. A near-net-shape product of Al-Al3Fe FGM, in the form of a cup, was successfully fabricated through the semi-solid backward extrusion process during which lower test temperatures produced better results. The volume fraction concentration of Al3Fe appears to be independent of the test temperature and over 60 vol% around the bottom cup region, decreasing gradually towards the cup wall region. The shape of coarse Al3Fe particles changes to a more fine fibrous shape at some locations whilst remaining unchanged in others. The shape change mechanism appears not to be due to melt flow erosion, dissolution and/or re-crystallization, but rather due to viscous melt flow splitting of coarse particles. The brittleness of the coarse Al3Fe intermetallic compound that makes the application of conventional plastic deformation methods impossible appears not to be the case during near-net-shape forming over eutectic melting point. Shore hardness increases with increasing volume fraction of Al3Fe particles and following semi-solid forming the product appears to be harder than before. This appears to be the result of refining of Al3Fe particles through shear stress introduced by liquid Al flow during semi-solid forming. Fabrication of FGMs having fine fibrous Al3Fe phase, appears to be possible if the forming process is carried out at an optimum condition. English