巻号一覧
37 巻, 7 号
選択された号の論文の47件中1～47を表示しています
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平井 敏雄1990 年 37 巻 7 号 p. 912
発行日: 1990/09/25
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) -
高橋 秀明1990 年 37 巻 7 号 p. 913-917
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーA national project for the development of Functionally Gradient Materials (FGMs), which is directed toward ex-ploiting basic technologies required for the development of super-heat-resistant materials capable of space plane applications, is in progress. The FGM is a new composite material whose composition and microstructure vary continuously from place to place in ways designed to provide it with the maximun, function of mitigating the induced thermal stress. This paper reviews the current status of the FGM program with special focus on the research activities on evaluation procedure for FGMs. In order to provide material design data and evaluate the mechanical and thermal barrier functions of FGMs, the following testing methods are being developed: (1)small punch test, (2)laser heating thermal shock test. Brief descriptions for these testing procedures and the experimental results obtained to data are given. Finally, the significance of the standardization of the testing procedures and the establishment of a material property data base are discussed for the interdisciplinary interaction among the three research groups.抄録全体を表示PDF形式でダウンロード (2408K) -
北口 三郎, 下田 信之, 斉藤 亨, 滝川 浩, 古賀 正実知1990 年 37 巻 7 号 p. 918-921
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーA method synthesizing Functionally Gragient Materials (FGM), in which the chemical composition gradually varies, was developed by employing Low Pressure Plasma Spraying (LPPS). Desirable FGM-coating, 30mm in the diameter and 1mm thick on a copper or stainless steel substrate was obtained by concurrently mixing ceramics powders and metal powders in plasma arc. The FGM coating made by this process was proved very resistive against thermal shock under a CO2 laser lighting and a large temperature difference test by a 30kW-Xe arc lamp.抄録全体を表示PDF形式でダウンロード (4567K) -
川崎 亮, 広瀬 仁幸, 橋本 等, 渡辺 龍三1990 年 37 巻 7 号 p. 922-928
発行日: 1990/09/25
公開日: 2009/12/04
ジャーナル フリーA powder spray stacking apparatus has been developed for fine stacking of mixed powders. Functionally gradient material has been successfully fabricated using this process, which has fine microstructural transition from stainless steel to zirconia ceramics.
Mixing ratio of metal and ceramic powders in the suspension using ethanol as a solvent was varied gradually by the computer control. Deposited products, which were prepared by spraying and depositing the suspension on preheated substrates, were CIP'ed, encapsulated and HIP'ed. Detailed observation of the microstructure has revealed that this process could precisely control the various composition profile with the minimum control size of 0.01mm. It has been shown that the thermal shock resistance of spray formed FGM'was significantly higher than that of monolithic zirconia ceramics.抄録全体を表示PDF形式でダウンロード (3169K) -
結城 正弘, 村山 敏一, 入沢 敏夫, 川崎 亮, 渡辺 龍三1990 年 37 巻 7 号 p. 929-932
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーThe equipment for temperature gradient sintering by laser beam irradiation which is suitable heat source for heat control and local heating was developed. In this equipment, the laser beam(YAG-laser, 1.06μm, maximum power300W) will be scanned by two oscillating mirrors and will irradiate the specimen setted in the chamber. Temperature profiles in PSZ(Zirconia-stabilized with 3%Yttria) irradiated by laser beam with power 200W were calculated by steady state FEM analysis. The calculated result showed that the temperature of top surface was about 2100K and the temperature gradient between top and bottom surface was about 300K. By means of this laser irradiation condition, PSZ and PSZ/Mo-functionally stepwise gradient material sintered in temperature gradient could be obtained.抄録全体を表示PDF形式でダウンロード (3015K) -
高倉 敏一, 田中 功, 宮本 欽生, 山田 修1990 年 37 巻 7 号 p. 933-936
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーFunctionally gradient materials (FGM) of TiB2-Ni system were synthesized and simultaneously densified by a gas-pressure combustion sintering under the pressure of 100MPa. This method is expected as a fast and economical process to fabricate dense refractory materials of ceramics, intermetallic compounds and FGM.
The combustion temperature affects the microstructure and densification of the products. It was particularly important for densification to decrease the combustion temperature below the boiling point of Ni by adding dilutents of Ni and/or TiB2 into reactants. The addition of excess Ti acted as a getter of oxygen impurities and enhanced the densification of FGM.抄録全体を表示PDF形式でダウンロード (2378K) -
松崎 祐司, 藤岡 順三, 南方 俊一, 宮本 欽生1990 年 37 巻 7 号 p. 937-941
発行日: 1990/09/25
公開日: 2009/12/04
ジャーナル フリーThis paper describes a process for the fabrication of Functionally Gradient Materials(FGM) by the Gas-pressure Combustion Sintering which is a combined process using combustion synthesis(SHS) and the hot isostatic press. We fabricated the (MOSi2-SiC) /TiAl FGM, for the purpose of applying then to airframes and engines of hypersonic vehicles because of the good oxidation resistance, the high temperature strength of the MoSi2-SiC composite and the excellent specific strength of TiAl. We clarified that the distribution of the chemical composition of FGN has a great influence on the residual stress which is generated during the process of fabrication and examined a boundary condition of the compositional distribution parameter to reduce the critical residual stress below the fracture strength.抄録全体を表示PDF形式でダウンロード (4600K) -
伊藤 義康, 高橋 雅士, 柏谷 英夫1990 年 37 巻 7 号 p. 942-946
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーThe residual stress of functionally gradient materials produced by uniform heating process was studied in comparison with two-layer composites produced by solid state bonding. Disk shape models of stabilized zirconia/Ni based alloy (INCO X718) composites were chosen for finite element method (FEM) analysis of residual stress and deformation. It was verified that the residual stress decreased by use of the gradation technique. Especially, the stress singularity at the edge of interface of two-layer composites could be disappeared in case of functionally gradient materials. The results indicated that the non-dimensional residual stress τra at the thickness center increased with increasing the disk iameter and the Young's modulus ratio in the range of 2R/H=10 to 40. And, the non-di-mensional residual stress σt, σr at the surface increased with increasing the disk diameter ana the Young's modulus ratio over 2R/H=40. They mean that the separation cracking occurs in case of small functionally gradient materials and the surface cracking occurs in case of large functionally gradient materials. Namely, it is too difficult to produce the large funtionally gradient materials for the surface cracking. Also the residual deformation decreased by use of the gradation technique, and the results indicated that the non-dimensional displacement Vm x at disk edge increased with increasing the disk diameter and in the range of 2R/H=10 to 40.抄録全体を表示PDF形式でダウンロード (351K) -
木村 修, 渡辺 秀美1990 年 37 巻 7 号 p. 947-950
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーThis paper discusses the effects of a film at the particle/matrix interface in a particle-dispersed ceramic composite on the stresses due to thermal contraction mismatch upon cooling by using the formal elastic theory. The dispersed particles are assumed to be spherical and uniformly covered with films of FGMs or of other materials having various properties.
Analysis is conducted for the particle/matrix systems, in particular for SiC/Al2O3 and Al2O3/MgO composites. Reduction of thermal stresses is shown to occur when the interfacial film is a sufficiently thick FGM film or has a lower Young's modulus.
Also, when the particle has a lower thermal expansion coefficient than the matrix, the interfacial stresses decrease as the thermal expansion coefficient of the film increases.抄録全体を表示PDF形式でダウンロード (203K) -
斎藤 雅弘, 高橋 秀明, 橋田 俊之, 佐々木 眞, 平井 敏雄1990 年 37 巻 7 号 p. 951-956
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーModified Small Punch(MSP) Test using Acoustic Emission (AE) technique was examined on silicon carbide (SiC), pre-paring by sintering or chemical vapor deposition (CVD), from room temperature to very high tenperatures. MSP testing method based on miniaturized test technique was developed to evaluate the each fracture property from once a test, and is effective especially for the material evaluation at the initial developed stage on new materials such as Functionally Gradient Materials (FGMs). From these results, the change of mechanical properties with the difference of crystal structure and fabrication method on ceramics was examined. Furthermore, micro fracture process for ceramics at high temperature environment was evaluated by AE data and the cause for the strength degradation of ceramics at very high tertperatures was also discussed. The proposed simultaneous use of MSP test and AE method could provide a great deal of the useful information on the microscopic fracture mechanism in siticon carbide ceramics at very high temperatures.抄録全体を表示PDF形式でダウンロード (3940K) -
宮脇 和彦, 橋田 俊之, 高橋 秀明1990 年 37 巻 7 号 p. 957-961
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーThis paper presents some results of transient thermal transfer and thermal stress analyses of thermal barrier coatings subject to rapid heating. The objective of this study is to develop a laser heating test for evaluating the thermal shock resistance of functionally gradient materials (FGMs). The numerical calculations are conducted on plasma-sprayed single-layer ZrO2 (stabilized with 8% Y2O3), and FGM which consists of multilayer with varying mixture ratios of ZrO2 and NiCrAIY deposited on a stainless steel substrate. The thermal barrier coatings with temperature dependent thermal and mechanical properties are heated by laser impingement. The transient thermal stress distribution is determined based on temperature profile using a finite element method. The intensity distribution within laser beam is taken into account. Based on the numerical results, the effect of the gradient composition in the FGM on the thermal shock resistance is examined. It is shown that the numerical analysis can provide a quantitative description of the enhanced thermal shock resistance of the FGM.抄録全体を表示PDF形式でダウンロード (289K) -
永田 佐登司, 足立 直人, 熊川 彰長, 佐々木 正樹, 前田 修平, 平田 徹1990 年 37 巻 7 号 p. 962-965
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーThe evaluation method on the thermal fatigue properties of Functionally Gradient Material ( FGM ) in the high temperature difference field was developed.
The top surface of the specimen was heated by light beam from 30kW-Xe arc lamp, and the bottom was cooled with liquid nitrogen in a vaccum vessel. The specimen was cyclically heated by opening and closing a shutter.
Thermal fatigue tests were conducted for some FGM specimens. such as PSZ/Ni-Cr and TiB2/Cu-FGM. The effective thermal conductivity of these FGM specimens decreased as the number of thermal cycles increased. These results showed that it was possible to evaluate the thermal fatigue property of FGM based on the change of the effective thermal conductivity.抄録全体を表示PDF形式でダウンロード (1057K) -
佐々木 眞, 平井 敏雄, 橋田 俊之, 高橋 秀明1990 年 37 巻 7 号 p. 966-967
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーDeposits having a compositional distribution from C to SiC were fabricated on a graphite substrate by chemical vapor deposition (CVD). The thickness of the SiC/C FGM are 0.8 mm and 1.8 mm. Under local heat con-ditions (heat flux, 5.8 MWm-2), SiC Non FGM(NFGM) suffered cracking under the same conditions and vertical cracking was observed out of heating zone. SiC/C functionally gradient material (FGM) did not suffer cracking and was shown to be superior in thermal shock resistance. The cracking was considered to be due to the hoop tensile stress generated on un-heated surface of the specimen.抄録全体を表示PDF形式でダウンロード (842K) -
新原 晧一1990 年 37 巻 7 号 p. 970
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (87K) -
香山 晃, 佐東 信司1990 年 37 巻 7 号 p. 971-975
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーA brief review of the works to develop multi filament type PCS-SiC fiber, NICALON, reinforced Al matrix composite materials is provided. The improvement in tensile strength was the major effort and the precise investigations to understand microstructure to mechanical property correlations was successfully carried out through these works. Fabrication process of SiC/Al wire preforms by liquid infiltration method was optimized to minimize mechanical property degradation of SiC fibers, to suppress defects both in matrices and interfaces. Furthermore, Al-Ni alloys were studied for the microstructur-al evolution under electron damage and neutron radiation effects on these composites materials.抄録全体を表示PDF形式でダウンロード (6366K) -
佐東 信司, 香山 晃1990 年 37 巻 7 号 p. 976-979
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーElastic modulus and internal friction of SiC fiber unidirectionally reinforced Al matrix composite materials were investigated by means of lateral vibration method. Anisotropy of elastic modulus was measured and was found to be well coincided with a simple rule of mixture. A dependence of internal friction on cyclic loading showed a strong increase at the initial stage and reached to the saturation stage. Lateral vibration internal friction measurement method was found to be very effective to detect very initial stage of fatigue process found in fiber reinforced metal matrix composite materials.抄録全体を表示PDF形式でダウンロード (250K) -
大空 靖昌, 松永 賢二, 鈴木 道之, 中川 成人, 山村 武民1990 年 37 巻 7 号 p. 980-983
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーThe shearing test of the unidirectionally reinforced aluminum matrix composite by a continuous Si-Ti-C-O fiber (Tyranno fiber(R)) was carried out to evaluate the bonding ability between the fiber and the matrix of this composite. Both longitudinal and transverse shear strengths were 0.13 GPa, and the fracture occurred at the matrix itself because of good wettability of the fiber for aluminum. The excellent compatibility of Si-Ti-C-O fiber for the aluminum matrix composite was found to be due to the mutual diffusion of aluminum atoms from the matrix to the fiber and also of silicon atoms from the fiber to the matrix after the fabrication of the composite.抄録全体を表示PDF形式でダウンロード (2806K) -
菅沼 克昭, 松永 耕二, 佐々木 元, 藤田 輝昭, 新原 晧一, 中平 敦, 原田 秀文, 鈴木 信幸1990 年 37 巻 7 号 p. 984-986
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーSqueeze casting of potassium titanate whisker reinforced 6061 aluminum alloy matrix composites was examined. Effects of distribution of whisker in a preform was varied by a milling of whisker in water and by the surface activation treatment of whisker during stiring in water by adding surface activation agent. The surface activation treatment is proved to be the best treatment for make uniform distribution of whisker in a preform, i.e. in a composite. Then, this treatment increased the tensile strength up to 350 MPa and the Young's modulus up to 92 GPa and reduced the thermal expansion coefficient down to 16×10-6 /K. These properties are desiarble for industrial uses of aluminum matrix composite combined with the low cost of composite. Silica binder used to fix the whisker preform was reacted aluminum melt during casting and dis-appeared from the FRM. Instead, small particles of alumina was formed on the whisker by the reaction between whisker and aluminum.抄録全体を表示PDF形式でダウンロード (3613K) -
今津 逸郎, 深沢 稔, 小田 高土1990 年 37 巻 7 号 p. 987-990
発行日: 1990/09/25
公開日: 2009/12/04
ジャーナル フリーConcerning SiC whisker reinforced aluminum alloys, the effect of SiC whisker's diameter and the bonding strength at the interface between whiskers and matrix to the mechanical properties of composites were investigated. The results of this study were summarized as follows:
1. The effect of larger diameter SiC whisker, which is 1.1μmφ, to the mechanical properties of composite was approximately equal to that of smaller diameter SiC whisker, which is 0.5μmφ.
2. Tensile strength of the composite made up of carbon coated SiC whisker obviously declined. So strong bonding at the interface between whisker and matrix was very important to good mechanical properties of the composite.抄録全体を表示PDF形式でダウンロード (2462K) -
砂田 久吉, 深浦 健三, 泉 久司, 三澤 泰之1990 年 37 巻 7 号 p. 991-994
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーFatigue strength of aluminum reinforced by SiC whiskers was studied under rotating bending moment at elevated temperature in air . The tests on five kinds of whisker volume fractions (0, 5, 10, 15 and 20) were carried out. The results obtained were summarized as follows;
(1) The tensile strength of the composite material becames higher as the volume fraction of whiskers increases. And the tensile strength decreases with increasing the test temperature.
(2) The fatigue strength at room temperature increases proportionally with the increase of the volume fraction of whiskers. The fatigue strength at elevated temperatures follows the relatonship with the volume fraction as well as the tensile strength.
(3) The typical striation on the fatigue fracture surface becomes obscure and the surface becomes rougher as SiC volume fraction increase.抄録全体を表示PDF形式でダウンロード (5108K) -
加賀 寿, 下野 功, 田谷 嘉浩, 高村 巧, 菅原 智明, 片山 博1990 年 37 巻 7 号 p. 995-1000
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーWe have developed a vacuum mechanofusion system which maintains a residual pressure in the reaction chamber lower than 10-2 Pa during mechanofusion processing. Using this system, we success-fully coated Cu powders of 30μ m diameter with Al2O3 powders of 0.5μ m diameter.
The effects of the residual pressure and the Al2O3 content on the mechanofusion behavior of Cu/Al2O3 particles were investigated by observing the particle size distribution and the appearance of the mechanofused particles. The mechanofusion behavior of Cu/Al2O3 particles strongly depended on the residual pressure, i.e., the volume percent of uncomposite particles decreased as the residual pressure became lower. The degree of coating promotion was dependent on the Al2O3 content. The adhesion of composite particles became stronger with decrease of Al2O3 content, especially when Al2O3 content was smaller than 1.0 wt%.抄録全体を表示PDF形式でダウンロード (3116K) -
渡辺 秀美, 木村 修1990 年 37 巻 7 号 p. 1001-1003
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーThe improvement of fracture toughness of Al2O3 ceramics is required for the application structural materials. In this paper, for this purpose Pd (palladium) particles dispersion in Al2O3 is studied. Powder contents of Pd-particles in the sintered body were 0, 10, and 15 vol% respectively. The mixtures were hot-pressed at 1350°C for 45min in nitorogen atmosphere at a pressure of 30MPa. Addition of Pd-particles is found to increase the fracture toughness of Al2O3 from 4 to 5 MPam1/2 at 10vol%.
Microstructural observations indicate that the toughness increase is a result of crack deflection around the Pd-particles.抄録全体を表示PDF形式でダウンロード (1175K) -
間渕 博, 中山 豊, 泰山 正則1990 年 37 巻 7 号 p. 1004-1008
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーThe composites were prepared from elemental powders, i.e. titanium powders and aluminum powders. The powder mixtures, with a composition Ti50Al50(in atomic %), were cold isostatically pressed, and sintered under a nitrogen gas of 0.1 MPa for a time of 5 min at 1273 K. Consequently, (TiAl+Ti3Al) and Ti2AlN were produced by the combustion-reaction, and the resulting composite had about 30 vol% Ti2AlN in the matrix TiAl. It was found that the composites have good strength and ductility at both room and elevated temperatures. Therefore, present investigations have considarable interest as a new combustion-reaction process to make a composite material.抄録全体を表示PDF形式でダウンロード (3466K) -
立沢 清彦, 松原 秀彰, 木原 諄二, 岩間 一浩1990 年 37 巻 7 号 p. 1009-1012
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーConditions for electroless nickel plating on TiC powders were examined, and sintering behavior and structure of sintered compacts using the TiC-Ni composite powder were studied. Annealing TiC powder in hydrogen prior to plating improved nickel plating on TiC powder and densification of composite powder compacts. While for Ni-B plating with dimethylamine borane as the reducing agent, surface activation was necessary for coating, but for Ni-N plating with hydrazine as the reducing agent, nickel deposits were directly formed on TiC powder annealed in hydrogen. Dense compacts made of TiC-Ni composite powder were obtained by liquid phase sintering at 1623K. The contiguity of carbide particles in sintered compacts was markedly reduced by using composite powder, compared with using mixed powder of TiC and Ni.抄録全体を表示PDF形式でダウンロード (3157K) -
中西 宏之, 田中 功, 岡本 平, 宮本 欽生, 山田 修1990 年 37 巻 7 号 p. 1013-1016
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーA new sintering method using HIP which we call the reaction heat sintering has been developed.
This method enables to densify the ceramics instantaneously by the high heat supply from the combustion agent of Ti and C under argon gas pressure. Dense TiC ceramics fabricated without additives showed a unique microstructure having the micro pores being dispersed within TiC grains and high fracture toughness of 5 MPam1/2. Nickel metal powders were added in various compositions up to 90 wt% and densified. Based on these experiments, the functionally gradient material of TiC-Ni system was fabricated by the reaction heat sintering.抄録全体を表示PDF形式でダウンロード (1983K) -
松下 純一, 長島 秀夫, 齋藤 肇1990 年 37 巻 7 号 p. 1017-1020
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーMicrostructure of pressureless sintered TiB2 with Cr and C additives was investigated. Cr and C play an effective role in the densification of TiB2. TiB2 sintered with 6.2wt% Cr and 1.3wt%C exhibited a bending strength of 405MPa and Vickers hardness of 23GPa.
According to the X-ray diffraction date, TiC and CrB were formed at the grain boundaries of TiB2. Also, the solid solution between TiB2 and Cr was recognized.
The SEM observation supported that a liquid phase was significantly concerened in the sintering of TiB2. The fracture surface of TiB2 sintered with Cr and C showed both transgranular and intergranular fracture mode.抄録全体を表示PDF形式でダウンロード (2620K) -
蜂須賀 武治1990 年 37 巻 7 号 p. 1021-1028
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーIt had been confirmed in the previous work that 70%TiC-15%TiN-7%Mo2C-8%Cr3C2 ceramic composite showed distinguished sinterability similar to liquid phase sintering alloys. That is to say, the complete dense bodies of the composite can obtain by means of sintering at 1623K. Present study was undertaken to reveal the effect of microstructure on properties of the dense ceramic composite in relation to sintering temperature up to 1873K.
The ceramic composites were strengthened, toughened and hardened with accompanied grain growth according to rise of sintering temperature. Bending strength, fracture toughness and Vickers hardness reached the values of about 780 MPa, 4.65 MPa·m1/2 and 24.0 GPa respectively in the specimen sintered at 1823K. The value of strength corresponds to rise of about 300 MPa compared with that of TiC-Cr3C2 system.
It was confirmed in fracture test that the composites have the characteristics of easy branching property of cracks and of slow velocity in crack propagation, which resulted remaining of many branched cracks in the specimens after fracture.
Morphology of cracks in fractured specimens elucidated multi-toughening phenomena in the ceramic composite, comprising branching and deflection of cracks and micro-cracking. And, the rise of strength was presumed due to R-curve behaviour.抄録全体を表示PDF形式でダウンロード (10284K) -
蜂須賀 武治1990 年 37 巻 7 号 p. 1029-1036
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーIt has been confirmed that the dense multi-component ceramic composites consisting of 40% TiC-15% TiN-4%Mo2C-25%WC-8%HfC-8%Cr3C2 showed strengthening and toughening with accompanied grain growth according to rise of sintering temperature up to 1873K, in the same way as in TiC-TiN-Mo2C-Cr3C2 ceramic composite of previous work. That is to say, the toughening was occurred by multi-toughening mechanism comprising branching and deflection of cracks and micro-cracking.
Among these energy absorbing phenomena in crack propagation, branching of cracks and micro-cracking were more occurred in the composite than previous one, resulting higher fracture toughness. It was presumed that the higher fracture toughness was caused by increase in Young's modulus of matrix and enlargement of difference in thermal expansion coefficients between matrix and low chromium carbide particles, due to addition of large amounts of tungsten carbide in the composite. The fracture toughness showed good correlation with calculated sizes of plastic zone formed at tip of cracks in the both composites.
It was also clarified that strengthenings in the both composites were depending not on decrement of defect size but on enhancement of fracture stress based on R-curve behaviour.抄録全体を表示PDF形式でダウンロード (3913K) -
蜂須賀 武治1990 年 37 巻 7 号 p. 1037-1043
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーTo clarify the cutting properties for machining of carbon steel, two TiC-Cr3C2 base multi-component ceramic composites consisting of 70%TiC-15%TiN-7%Mo2C-8% Cr3C2 and 40%TiC-15% TiN-4%Mo2C-25%WC-8% HfC-8%Cr3C2, which having been toughened by multi-toughening mechanism comprising branching and deflection of cracks and micro-cracking, were tested with continuous and
intermittent cutting by turning in dry condition, and discussed the results in conection with their mechanical properties. Cutting tests of other tool materials were also carried out, at the same time, to compare with their cutting properties in practical application.
Depending on high hardness of the ceramic composites, they showed excellent tool life in continuous cuttings at cutting speed of 3.33-5.0 m/s: four to eight times for TiC-base cermets and same to three times for Al2O3-base ceramic composites.
In intermittent cutting at low cutting speed of 1.67 m/s, the ceramic composites were caused chippings with comparatively small feed. But, because of the resistance for development of chippings to breakage, the ceramic composites showed best tool life among the tools tested. At higher cutting speed of 5.0 m/s, remarkable enlargements of feed occurring chippings were taken place, which resulted also best tool life among the tools. This was presumed to be due to high temperature properties of the ceramic composites.
We might expect from the fact above mentioned that many ceramic composite tools resembling to tested ones will be used in broad applications by the substitution of other tool materials.抄録全体を表示PDF形式でダウンロード (4102K) -
酸化工程星野 孝二, 河野 通1990 年 37 巻 7 号 p. 1044-1047
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーIt is difficult to sinter a tape-carted green sheet of Cu-Al alloy powder using ordinary sintering process in a reducing or vacuum atomosphere. The sintering process of a Cu-Al porous sintered alloy has been investigated to produce an anode of Cu-based alloy for a molten carbonate fuel cell. The results indicate that the green sheet can be sintered by the two-step sintering process; firing in the air to oxidize and sinter, and reducing in H2 gas. The reaction model which can explain the sintering process during the oxidation, is described.抄録全体を表示PDF形式でダウンロード (3638K) -
還元工程星野 孝二, 河野 通1990 年 37 巻 7 号 p. 1048-1051
発行日: 1990/09/25
公開日: 2009/12/04
ジャーナル フリーA new sintering process of the porous Cu-Al oxide alloy has benn investigated. The results indicate taht the green sheets of Cu-Al alloys powder made by tape casting process were able to be sintered by the two-step process; firing in the air to oxidize and sinter, and reducing in H2 gas. In the process, final porosity ratio was not affected by sintering temperature. Because a shrinkage due to a sintering reaction was restricted by the aluminum oxides layer which was formed in a powder during the oxidation-reduction process. The reaction model which can explain the sintering process during the reduction, is described.抄録全体を表示PDF形式でダウンロード (2289K) -
杉原 淳, 岡崎 清1990 年 37 巻 7 号 p. 1052-1055
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーWetting studies were carried out with electroceramics such as BaTiO3, Pb(Zr, Ti)O3 and Ba2Y1Cu3O7-x as the bases on which Ag and Ni were put in the vacuum at slightly higher temperatures than melting poit of the metal, and a contact angle was measured. And the effect of lead borosilicate glass on the wetting was studied with Ag containing the frit. For the cross sectional interfaces, EPMA analys is revealed that no Ag diffused into the base and the frit contributed to the in terfacial reaction.抄録全体を表示PDF形式でダウンロード (279K) -
山岸 千丈, 箱島 順一郎, 塚本 惠三, 秋山 豊1990 年 37 巻 7 号 p. 1056-1059
発行日: 1990/09/25
公開日: 2009/12/04
ジャーナル フリーβ-SiAlON⋅β-SiC composites were prepared from the β-SiAlON powder synthesized by carbo-thermal reduction and β-SiC powder(0-24wt% ) by pressureless sintering. The strength at room temperature of about 800 MPa remained relatively unchanged for composites containing up to 12wt% β-SiC. The strength at 1200°C increased for composites containing up to 9wt% β-SiC. The maximum value was 560 MPa. The fracture toughness for composites containing up to 12wt% β-SiC were higher than that for β-SiAlON alone. The maximum value was 5.4MPa√m for 6wt% β-SiC, and this was improvement of 15% in comparison with β-SiAlON alone. From optical microscope observation, improvement of K1c value was attributed to crack deflections. Vickers hardness increased with increasing β-SiC content, when composites were high density (about 100 %).抄録全体を表示PDF形式でダウンロード (935K) -
高田 寛, 中平 敦, 新原 晧一, 大西 宏司, 河波 利夫1990 年 37 巻 7 号 p. 1060-1062
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーEffects of SiC dispersions on mechanical properties have been studied for the natural mullite (fabricated from natural kaolin and Al2O3 powders)/SiC composite system. The natural mullite/SiC composites were prepared by pressureless reaction-sintering of natural kaolin, Al2O3 and SiC powders. These composites were composed of mullite with columnar-typed grains, fine SiC dispersions and amorphous grain boundary phases. The larger SiC particles (>0.3μm) were dispersed at the grain boundaries, while the finer SiC particles (<0.2μm) were located not only at the grain boundaries but also within the mullite matrix grains. The mechanical properties were strongly improved by these SiC dispersions. The Vickers hardness, fracture toughness and strength were approximately 10 GPa, 300 to 400 MPa and 2.5 to 3.0 MPam1/2, respectively. These values are much higher than those reported for monolithic natural mullites and are comparable to those for advanced mullite ceramics.抄録全体を表示PDF形式でダウンロード (3489K) -
寺内 信哉, 佐藤 次雄, 遠藤 忠, 島田 昌彦1990 年 37 巻 7 号 p. 1063-1066
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーZirconia powders containing 3mol% Y2O3 were mixed with SiC powders or SiC whiskers by ball-milling and were uniaxially pressed at 1OMPa prior to cold isostatic pressing at 200MPa. The green bodies were sintered at 1450 and 1500°C for 1-18 hours under a stream of 95vol%He-5vol%CO gas, and then were hot isostatically pressed at 1450°C and 15OMPa for 1 hour in an Ar gas atmosphere. The density of HIPed bodies increased with increasing that of presintered bodies. The presintered bodies of Y-TZP/2.5vol%SiC particle composites with a relative density above 93% could be densified to almost fully theoretical density by HIPing. The bending strength of the Y-TZP/SiC(particle) and Y-TZP/SiC(whisker) composites increased by hot isostatic pressing, while the values of the Weibull modulus did not increase.抄録全体を表示PDF形式でダウンロード (187K) -
衝突速度と角度の効果和田 重孝, 渡辺 直義1990 年 37 巻 7 号 p. 1067-1073
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーErosive wear tests were carried out for nine specimen / particle pairs which were assorted three specimens, SiC, Si3N4 and glass with three particles, SiC, Al2O3, and glass, at the impact velocity (V) of 50-300m/s and at the impact angle(θ) of 20-80°. The value of n in the equation for the erosive wear rate (W), W∞Vn.sinθm, was (3.0-3.6) for all pairs. The value of m was (0.63-1.2) for the pairs of SiC and Si3N4 specimens with Al2O3, particle, and (1.4-1.8) for the other pairs. The difference in the m value was explained as the results of the difference in the erosive wear mechanism caused by the differences of the fracture toughness(KIc) between the specimens tested and the frangibility between the particles, used.抄録全体を表示PDF形式でダウンロード (1536K) -
和田 重孝, 渡辺 直義, 右京 良雄1990 年 37 巻 7 号 p. 1074-1077
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーSialon composites with different ratios of α'-Sialon to β'-Sialon were made by the hot-pressing method, and their erosive wear were tested using SiC and A1203 particles as well as monolithic ceramics such as α-Sialon, β-Si3N4 and sintered SiC. The Sialon composites exhibited unti-erosion properties superior to those of the monolithic ceramics. The Sialon composites posses the hardness of about 23GPa which is as large as that of α-Sialon and the excellent fracture toughness of 7.5MPam1/2 which is similar to that of β-Si3N4. The superior unti-erosion properties of the Sialon composites resulted in their excellent mechanical properties.抄録全体を表示PDF形式でダウンロード (2026K) -
合金鋼の切削千徳 英一, 熊谷 幹人, 柏本 浩伸, 藤村 善雄1990 年 37 巻 7 号 p. 1078-1081
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーIn recent years. many ceramics and cermet tools with various kinds of properties have appeared on the market. The purpose of this paper is to clarify the tool life of TiC-Cr3C2 compound ceramics and TiC-Al2O3 ceramics tool on the machining of alloy steel at high cutting speed. The tool life was studied and discussed upon both continuous and Intermittent cutting by turning. The cutting speed for examination was 200 m/min, 250 m/min and 300 m/min. The results obtained are as follows; (1) In continuous cutting, tool life of TiC-Cr3C2 compound and TiC-Al2O3 ceramics tool was larger than those of cermet and ceramics tools. (2) The wear mechanism of TiC-Cr3C2 compound ceramics tool was pile up micro chipping on the tool edge. (3) In intermittent cutting, TiC-Al2O3 ceramics tool was appeared the longest tool life. (4) Since TiC-Cr3C2 compound ceramic and TiC-Al2O3 ceramics tool shows good cutting performance to the alloy steel, it is considered the cermet tool will be replaced by these tools.抄録全体を表示PDF形式でダウンロード (1273K) -
勝村 祐次, 小堀 景一, 鈴木 寿1990 年 37 巻 7 号 p. 1082-1087
発行日: 1990/09/25
公開日: 2009/12/04
ジャーナル フリーAt first, oxidation resistance of Al2O3 based ceramics having a single addition of different carbides was investigated, with the result that the ceramics containing SiC in powder(SiC) or whisker(SiC(w)) form showed the highest resistance to oxidation. Attending to this result, the following studies were made. Some properties of Al2O3-SiC ceramics was first studied. Then the improvement of sinterability of this ceramics due to adding SiO2 was studied. Next, cutting performance of Al2O3-SiC ceramics was examined in comparison with the other ceramics tools, and it was made clear that flank wear of Al2O3-SiC tool became larger and smaller than that of Al2O3-TiC tool and Al2O3- SiC(W) one, respectively. Finally, interfacial reaction between Ni and the three sorts of ceramics as above was studied to describe the phenomenon. The outlines of these results were shown.抄録全体を表示PDF形式でダウンロード (5091K) -
平井 敏雄1990 年 37 巻 7 号 p. 1088-1091
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーComposites are composed of a matrix and a dispersion. Studies are underway to develop "nanocomposites" which have much smaller dispersion size in the order of nanometers. Here, the dispersion is a solid material. In recent years much research has focused on the development of new composites, termed "fine-composites", prepared by the in-situ CVD technique. In these composites, dispersion is no longer a solid materials but rather an element. "Fine-composites" are composed of materials (matrix) and elements (dispersion). Elements are various types of crystal structures, as well as certain preferred orientations, dispersion states, etc. The Y-Ba-Cu-O superconducting oxide films prepared by CVD are fine-composites composed of matrix of the (001) oriented YBCO and dispersions of the (100) oriented grains and very small Cu-rich flakes. Functionally gradient materials are also introduced as an example of fine-composite.抄録全体を表示PDF形式でダウンロード (2695K) -
伊藤 秀章, 杉本 啓, 服部 憲治, 岩原 弘育1990 年 37 巻 7 号 p. 1092-1095
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーA composite alumina (α-Al2O3) or iron powder which is coated with a homogeneous titanium nitride (TiN) thin film, was prepared by the rotary powder bed chemical vapor deposition (CVD) in the TiCl4-N2H2 reactant system. The dispersibility of coated powders and kinetics of the rotary powder bed CVD were investigated by varying important parameters such as the onset temperature of reactant gas introduction, the rotary speed of specimen cell, the grain size and charge amount. of powder. The adsorption pretreatment of the reactant gas on to rotating particles during raising temperature from 300°C to the deposition temperature was required to improve the particle dispersibility. No transition temperature from reactionto diffusion-limited regions for TiN deposition was observed in this CVD system. The deposition rate was inversely proportional to the total surface area of powder.抄録全体を表示PDF形式でダウンロード (1306K) -
上垣外 修己1990 年 37 巻 7 号 p. 1096-1100
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーThe critical grain size, below which the properties of the composites could be much different from those of the conventional composites, was estimated on the basis of the ideal strength and the specific surface energy. It is about 2nm-4nm for normal metal (Fe, Co), less than 1nm for oxides (Al2O3, MgO), and about 10nm for Si3N4, which suggests Si3N4 is one of the most advantageous materials for Nanometer Composites.抄録全体を表示PDF形式でダウンロード (289K) -
竹田 康彦, 元広 友美, 野田 正治1990 年 37 巻 7 号 p. 1101-1103
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーMicrostructures of thin films deposited obliquely from two sources were evaluated by means of 3D-computer simulation. The two sources were arranged in a common plane of incidence with equivalent angle of incidence, and hard spheres were rondomly generated from the two sources. Each hard sphere was assumed to travel on the straight line until it came in contact with one of the already deposi ?? ed spheres, and a sticking coefficient of unity and no relaxation after the deposition were assumed. The computer-generated thin film was shown to be a fine-composite consisting of nm-scale voids and columnar materials and to have two-dimensional anisotropic features, and in the deposited materials the spheres from one source tended to aggregate to one side of the column and the spheres from the other source to the other side of the column. The oblique deposition was suggested to be a useful method to generate a variety of nm-scale fine composites.抄録全体を表示PDF形式でダウンロード (134K) -
小山 孝, 西山 昭雄1990 年 37 巻 7 号 p. 1104-1107
発行日: 1990/09/25
公開日: 2009/12/04
ジャーナル フリーHigh strength Al2O3-30wt%Ti(C, N) composites were obtained by pre-sintering and HIPing. The maximum flexural strength was 1.1GPa for Al2O3-TiC0.7N0.3 and Al2O3-TiC0.5N0.5. The microstructure of Al2O3-Ti(C, N) composites was finer than Al2O3-TiC and Al2O3-TiN. In the cutting test of hardened steel, the flank wear was less and the tool life was longer with increasing N/(C+N) ratio in Al2O3-Ti(C, N) composites. This phenomenon could be explained by finer-grained microstructure and residual stress.抄録全体を表示PDF形式でダウンロード (2016K) -
岩田 美佐男1990 年 37 巻 7 号 p. 1108-1112
発行日: 1990/09/25
公開日: 2009/12/04
ジャーナル フリーFiber reinforced silicon nitride and mullite composites, derived from continuous fiber, have been developed for applications requiring extreme toughness. They consisted of unidirectional carbon fiber reinforced matrics of the composites.
The composites were fabricated by a process consisting of slurry impregnation followed by hot pressing.
Measurement of sintering characteristics and observation of metallographic structure in the composites were carried out.
Flexural strength and fracture toughness of the composites at room temperature and at 1200°C were measured. Fracture toughness of silicon nitride matrix composite and mullite matrix composite were 28.1 MPa√m and 18.0 MPa√m at room temperature respectively.抄録全体を表示PDF形式でダウンロード (2880K) -
渡辺 秀美, 中平 敦, 新原 晧一1990 年 37 巻 7 号 p. 1113-1117
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーThe mechnical properties of 20vol%-SiC whisker reinforced A1203-matrix composites were investigated. Composites are produced using two types of whiskers with 0.5μm and 0.8μm in diameter respectively. Also, α and γ alumina were used as starting materials for matrix. The composites were prepared by hot pressing mixtures of alumina powder containing 20vol% SiC whisker. Composites with thick whisker are found considerably toughened compared with those with finer whikers.The maximum flexural strength reaches 900MPa for the composite with thicker whisker prepared by using γ-alumina as matrix.
Optical microscope observation of the ground surface of the composites and scanning electron microscope observation of the fracture surface of the composite indicate presence of crack deflection and whisker-pullout in toughened composite.抄録全体を表示PDF形式でダウンロード (1499K) -
高田 寛, 中平 敦, 田中 功, 新原 晧一, 内山 哲夫, 井上 茂夫1990 年 37 巻 7 号 p. 1118-1120
発行日: 1990/09/25
公開日: 2009/05/22
ジャーナル フリーA12O3 based composites dispersed with both SiC-whisker and ZrO2 particle were successfully fabricated by hot-pressing. The mechanical properties of these composites were largely improved by the multiple toughening of SiC whisker and ZrO2. Fracture strength 1060MN/m2 and fracture toughness 7.5MN/m3/2 were observed for the A12O3/15vol%SiC whisker/15vol%Zr02 composites. For these composites, the transient-tensile-thermal stresses by rapid quenching technique into water were applied to promote the tetragonal-monoclinic transformation of ZrO2 without increasing the surface flaw. As results, the strength improvement over 30% was realized by the compressive stress associated with the tetragonal-monoclinic transformation of ZrO2 at the near surface which was accelerated by thermal stresses with water quenching after the light grinding with diamond wheel.抄録全体を表示PDF形式でダウンロード (196K)
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