巻号一覧
45 巻, 3 号
選択された号の論文の17件中1～17を表示しています
- |<
- <
- 1
- >
- >|
-
平井 敏雄1998 年 45 巻 3 号 p. 198
発行日: 1998/03/15
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (66K) -
西田 俊彦, 渡辺 龍三, 遠藤 忠, 小野 勝道, 平井 敏雄1998 年 45 巻 3 号 p. 199-204
発行日: 1998/03/15
公開日: 2009/05/22
ジャーナル フリーThe advancement status of the research project supported by the Ministry of Education, Science, Sports and Culture, Japan with Grant-in-Aid entitled "Physics and Chemistry of Functionally Graded Materials (FGM)" is presented. In this project, refractory materials for relaxation of thermal stresses are left aside, and emphasis is placed on: 1) the development of new processes for the preparation of FGMs, and development of new materials with 2) electromagnetical functionally graded properties, 3) thermoelectric and optical functionally graded properties, as well as 4)chemical and bio-chemical functionally graded properties. In addition, after showing several results of recent researches, the necessity of a research organization which allows the accumulation and synergy of the obtained results is emphasized.抄録全体を表示PDF形式でダウンロード (582K) -
山田 葉子, 飯島 宏康, 渡辺 龍三1998 年 45 巻 3 号 p. 205-210
発行日: 1998/03/15
公開日: 2009/05/22
ジャーナル フリーThe rheological behavior of hydroxyapatite and partially stabilized zirconia mixed slurries is investigated in order to study the production of hydroxyapatite / zirconia functionally graded materials by slurry dipping method. The purpose of this material is to use as a dental implant material. The rheological behavior of hydroxyapatite and zirconia, which strongly contributes to the resultant thickness of FGM layer, is different between hydroxyapatite (Newtonian fluid) and zirconia (non-Bingham plastic fluid). The mixed slurries.of hydroxyapatite and zirconia slurries show the strong contribution of zirconia when the shear rate is low, but the rheology of hydroxyapatite is dominated when the shear stress is high. On the other hand, the optimum dispersant concentration changes linearly with change in the composition of hydroxyapatite and zirconia.抄録全体を表示PDF形式でダウンロード (2112K) -
湯浅 栄二, 河村 忠治, 鈴木 航太1998 年 45 巻 3 号 p. 211-215
発行日: 1998/03/15
公開日: 2009/05/22
ジャーナル フリーTitanium and boron powders having a molar ratio of Ti/B=1/2 were mixed with copper powder in four mixture ratios and then they were mechanically alloyed for 72ks by using planetary ball mill. The mechanically alloyed powders were piled up progressively from low amount of (Ti/B) to high contents in four layers. The lamellar compact was producted by vaccum hot pressing for various treating times at 873K. Consolidation of the lamellar compact as functioally graded material was estimeted from standpoints of densification and mechanical strength of the compact and microstructural change in the each alloy layer during vaccum hot pressing. The lamellar compact is homogeneously densely formed without curved contours by the vaccum hot pressing for shorter treating time at lower temperature than conventional sintering after cold compacting. The lamellar compact hot-pressed in the vaccum atmoshere have high rupture strength in the bending.抄録全体を表示PDF形式でダウンロード (3792K) -
Mamoru Omori, Akira Okubo, Toshio Hirai1998 年 45 巻 3 号 p. 216-219
発行日: 1998/03/15
公開日: 2009/05/22
ジャーナル フリーThermal conductive composites were formed from thermoplastic polyimide and A1N powders, and functionally graded materials (FGMs) were fabricated from those composites and Cu powder using a spark plasma system. A high pressure of 245 MPa was required to obtain dense composites whose thermal conductivity was more than 10 W/m.K. The thermal conductivity of FGMs prepared at 39.2 and 245 MPa was 35 and 60 W/m.K.抄録全体を表示PDF形式でダウンロード (299K) -
大塚 愛子, 川崎 亮, 渡辺 龍三, 厳 泰永1998 年 45 巻 3 号 p. 220-224
発行日: 1998/03/15
公開日: 2009/05/22
ジャーナル フリーDisk-shaped functionally graded materials of copper/alumina system have been fabricated by spark plasma sintering(SPS process. The graded layer consists of symmetrical compositional transition of Cu/Al2O3/Cu, which allows to achieve high heat conduction, electrical insulation and excellent in-plane electrical conductivity. The use of the FGMs as a compliant pad of conduction type of thermoelectric power conversion system offers high thermal energy density through the thermoelectric cell, resulting in the increase of the efficiency of thermoelectric energy conversion.
This paper describes the process optimization including densification of metal-ceramic powder mixtures by SPS process, compositionally graded stacking of the mixed powders in a graphite die, the design of the compositional gradient on the basis of one dimensional heat conduction analysis and fabrication of Cu/Al2O3/Cu FGMs according to the predesigned compositional gradient.抄録全体を表示PDF形式でダウンロード (3336K) -
間渕 博, 津田 大, 河上 忠司, 森井 賢二1998 年 45 巻 3 号 p. 225-230
発行日: 1998/03/15
公開日: 2009/05/22
ジャーナル フリーDiffusion bonding of L10-type and L12-type alloys in the Ti-Al-Cr system was carried out to study graded diffusion layer. The Ti52Cr5Al43(L10) and Ti25Cr14Al61(L12) alloys were bonded at 1473 K for 1 h under 30 MPa, and annealed at 1423 K for 48 h in a vacuum(-10-4Pa). The resulting diffusion layer had Al-rich L10 phase layer of about 50μm and L12/L10 (coherent precipitated) two phase layer of about 50μm. The formation of the L12/L10 two phase layer is caused by the presence of the Ti-rich L12 phase field at higher temperatures. It was found that such diffusion layers have a preferable composition gradient and a graded linear expansion coefficient for functionally graded materials.抄録全体を表示PDF形式でダウンロード (6637K) -
森口 秀樹, 野村 俊雄, 津田 圭一, 磯部 和孝, 池ヶ谷 明彦, 森山 清子1998 年 45 巻 3 号 p. 231-236
発行日: 1998/03/15
公開日: 2009/05/22
ジャーナル フリーThe application of the material design concept of functionally graded material to cemented carbide tools to realize good wear resistance in the surface region, good fracture toughness in the inside and compressive residual stress in the graded composition zone has been studied to improve their cutting performance. To develop the new material, the cutting condition of broken tools was investigated and their cutting temperature distribution was measured by a newly developed cutting temperature measuring method. Then computer aided engineering (CAE) analysis using the finite element method (FEM) for the measured cutting temperature distribution was performed to determine the generated thermal stress by the change in cutting temperature distribution. The new material was developed with the aim to introduce the compressive residual stress that exceeds the calculated thermal stress. Functionally graded cemented carbides with the intended compressive residual stress could be developed and this new material has higher wear resistance, breakage resistance and thermal crack resistance than those of conventional cermet with uniform composition.抄録全体を表示PDF形式でダウンロード (6362K) -
李 敬鋒, 下田 信之, 川崎 亮, 渡辺 龍三1998 年 45 巻 3 号 p. 237-241
発行日: 1998/03/15
公開日: 2009/12/04
ジャーナル フリーTo attain fundamental information needed for designing functionally graded thermal barrier coatings, the strength and deformation properties of plasma-sprayed ZrO2-8wt%Y2O3/Ni-20wt%Cr composits with various compositions (0, 25, 50, 75, 100% Ni-20wt%Cr) were investigated from room temperature to 1200°C by means of small punch tests. The room temperature strength decreased rapidly with increasing ceramic content, from>1400MPa for metal to-100MPa for ceramic. The monolithic ceramic and ceramic-rich (75%) composites retained their strength up to 1200°C, whereas the compostions with>50 vol% metal showed lower strength at temperature above 800°C. All the plasma-sprayed materials showed low Young's moduli, being about 20-60% (lower bound for ceramic and upper bound for metal) of the theoretical data for fully dense composites, because of the microstructural features, such as high porosity and microcracks. Connection and propagation of microcracks (process-related defects) were found to occur before the eventual macrofracture of materials, consequently plasma-sprayed materials showed specific fracture behavior; nonlinear load-deflection curves were obtained in spite of brittle nature of the fracture.抄録全体を表示PDF形式でダウンロード (7386K) -
宮本 欽生, 林 君山, 山本 雅章, 田中 良平, 梅田 一徳, 田中 章浩1998 年 45 巻 3 号 p. 242-247
発行日: 1998/03/15
公開日: 2009/05/22
ジャーナル フリーSymmetrically graded materials in the systems of Al2O3/TiC/Ni with three different outer layers of the Al2O3, Al2O3-15vol%SiC, and Al2O3-20vol%a(WC-15wt%Co) were sintered by SHS/HIP. Strong compressive-residual-stresses were induced in the outer layers resulting in enhancement of their surface toughness, hardness and strength. These FGMs showed superior wear resistance comparing with the monolithic Al2O3 ceramics. The Al2O3-20vol%(WC-15wt%co)/TiC/Ni system showed the lowest friction coefficients of 0.28. However, the friction coefficients of these FGMs increased with temperature and the worn parts were rough.抄録全体を表示PDF形式でダウンロード (5292K) -
平塚 信之, 中村 陽平, 柿崎 浩一, 小林 秀彦1998 年 45 巻 3 号 p. 248-252
発行日: 1998/03/15
公開日: 2009/05/22
ジャーナル フリーNi-Zn ferrites with graded magnetic anisotropy for high frequency of megahertz order were prepared by the addition of CoO. When the CoO content increased, resonance frequency was expanded. However, initial permeability was decreased and anisotropy field was increased. Therefore we tried to prepare Ni-Zn ferrite with high initial permeability and high resonance frequency by the addition of graded CoO content. Troidal core samples were made to layer Ni-Zn ferrite with different CoO content. As the result, the sample which had large CoO content with inner layer, steep gradation and little Ni-Zn ferrite with outer layer showed excellent high frequency characteristics. The Ni-Zn ferrite added CoO with graded CoO content 0, 5, 0 wt.% had initial permeability of 80 for 20-60 MHz.抄録全体を表示PDF形式でダウンロード (403K) -
吉川 信一, 榎本 真介, 高橋 昌男, 廣田 健, 山口 修1998 年 45 巻 3 号 p. 253-256
発行日: 1998/03/15
公開日: 2009/05/22
ジャーナル フリーFormation of iron nitride was observed on Fe metal film rf-sputter deposited on polycrystalline AIN substrate as already reported on Fe metal/amorphous AIN multilayer. It was not found on the AIN thin film deposited on Fe metal substrate. These results suggest that Fe reacts with even crystallized AIN at their interface but that the iron nitride was not formed by nitrogen plasma during a reaction sputter deposition of AIN thin film. Multilayered Fe/ AIN thin films were also prepared by rf-sputter deposition changing applied rf-power at 30W and 100W. Giant magnetization component was observed at the multilayered interface because of the iron nitride formed by a solid state reaction between Fe and AIN. Small amount of nitrogen in AIN was assumed to be supplied to a-Fe forming a gradient of nitrogen content at the interface.抄録全体を表示PDF形式でダウンロード (365K) -
山根 久典, 森田 浩一郎, 窪田 俊一, 島田 昌彦1998 年 45 巻 3 号 p. 257-261
発行日: 1998/03/15
公開日: 2009/05/22
ジャーナル フリーSingle crystals of perovskite-type solid solution, K(TaxNb1-x)O3, having composition gradient were prepared by non-equilibrium cooling from a melt with the composition x=0.3. The size of the crystals was 1-2 mm. Electron microprobe analysis revealed that Ta content was rich in the core region of the crystals and decreased gradually to the edges with increasing Nb content. The composition gradient depended on cooling procedure. The dielectric constant measured at 500 kHz was in the range from 1000 to 4000 at temperatures from 290 to 720 K. The temperature dependence of dielectric constant reflected the composition gradient in the crystals.抄録全体を表示PDF形式でダウンロード (4022K) -
今里 州一, 坂口 茂也, 林 安徳1998 年 45 巻 3 号 p. 265-270
発行日: 1998/03/15
公開日: 2009/05/22
ジャーナル フリーCemented carbides with nickel binder have been widely used in place of cemented carbide with cobalt binder for improved corrosion resistance. For the cemented carbides of WC-Ni and WC-Ni-Cr alloys, the corrosion properties and the effects of carbon and Cr3C2 contents on their corrosion resistance were investigated by both immersion test and electrochemical measurement. In immersion test, dissolved elements and the amounts of them in 3%NaCl and 3%NaC1+0.1NH2SO4 solutions were analyzed by ICP spectroscopy. In electrochemical measurement, polarization curves in these solutions were measured. The anodic reaction was dissolution of the binder metals in both solutions, and the cathodic reactions were reduction of dissolved oxygen in 3%NaC1 solution, and reductions of both proton and dissolved oxygen in 3%NaC1+0.1NH2SO4 solution respectively. Anodic current densities in the polarization curves showed that corrosion resistance of WC-Ni-Cr was superior to that of WC-Ni. WC-Ni alloys with low carbon content showed the superior corrosion resistance to that of high carbon alloy, which was revealed by both conspicuous appearance of passivated region and low anodic current density in polarization curve.抄録全体を表示PDF形式でダウンロード (2291K) -
岩崎 智宏, 柳田 剛, 佐藤 宗武1998 年 45 巻 3 号 p. 271-275
発行日: 1998/03/15
公開日: 2009/12/04
ジャーナル フリーUsing a high-speed elliptical-rotor-type powder mill, composite particles of particulate Ag-Ni alloy and fine WC powder were prepared. The size distribution of the composite particles was measured by means of image analysis method. Effects of operating conditions on degree of progress of the compounding process and the composite particle size were investigated by observing temporal change in the particle size. The particle growth in the process was discussed applying a chemical reaction model to temporal change in the particle size. It was indicated that the parameters, the volume ratio of the particles to zirconia beads and the WC concentration, were the major controlling factors for the variation of the product particle size distribution.抄録全体を表示PDF形式でダウンロード (1815K) -
各種鋳鉄ローラー材との耐焼付性中村 秀樹, 山崎 啓二, 吉田 敏樹, 岡 宗雄, 飯塚 董, 内田 憲正1998 年 45 巻 3 号 p. 276-282
発行日: 1998/03/15
公開日: 2009/05/22
ジャーナル フリーIn connection with the limitation of flon gas usage in order to protect earth environment, the wear and galling of vanes and rollers for rotary type refrigerators and air-conditioners have been concerned. We have investigated vane materials, roller materials and their combinations which can stably be used in new refrigerants and lubricants. The evaluation method for wear resistance and galling resistance were established and those of tool steels and cast irons with different chemical compositions, structural factors, hardness and surface treatment conditions were investigated quantitatively. It was found for vane materials, that the addition of TiN particles, the increase of MC carbides, the increase of hardness and nitriding treatment were effective for preventing galling. Particularly, the materials having TiN particles and nitrided ones showed superior galling resistance to carbon vanes. It was also found for roller materials, that the galling resistance increased as P content in the material increased.抄録全体を表示PDF形式でダウンロード (6687K) -
木村 勇次, 高木 節雄, 後藤 秀人1998 年 45 巻 3 号 p. 283-288
発行日: 1998/03/15
公開日: 2009/12/04
ジャーナル フリーMicrostructures and mechanical properties were investigated for Fe-25mass%Cr-(1.5-1.8)mass%C alloys produced by mechanical alloying. Mixtures of iron, chromium and graphite powders were ball-milled in Ar atmosphere and then hot-pressed at 1273K in vacuum. Bulk materials obtained were subjected to annealing in temperature range of 873K-1473K, followed by air-cooling or water quenching. In Fe-25mass%Cr-(1.5-1.8)mass%C powder mixtures, nano-sized ferrite(αFe) grains are formed within powder particles after the ball-milling of 720ks. In powder with 720ks milling, M23C6 carbide finely precipitates during heating to the consolidation temperature, and this results in the formation of microduplex structure of (αFe+M23C6). Microstructure of the alloys are very sensitive to heat treatment conditions: Matrix is almost fully austenitic in annealing at around 1473K, while is martensitic in annealing at around 1273K. In the martensite structure formed in fine austenite grains of 1-2μm, it is characteristic that each prior austenite grain consists of only one set of laths with the same variant. The bending strength of MA bulk materials is much higher than that of materials produced by ingot-metallurgy process due to having the microduplex structures.抄録全体を表示PDF形式でダウンロード (7468K)
- |<
- <
- 1
- >
- >|