巻号一覧
46 巻, 12 号
選択された号の論文の8件中1～8を表示しています
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研究論文
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大西 忠一, 安見 和樹, 小川 恒一, 椿野 晴繁, 山本 厚之, 越智 秀1996 年 46 巻 12 号 p. 619-625
発行日: 1996年
公開日: 2007/03/30
ジャーナル フリーFriction welding of 2017 and 6061 aluminum alloys in as-received, solution heat treated and aged states was conducted under the optimum welding condition for as-received specimens. As friction-welded, tensile strength ofjoints was approximately equal to the mother 6061 alloy for every temper states. When the joints were post-heat-treated, brittle fracture occurred at the welding interface and/or pan-cake-like recrystallized boundaries in the vicinity of the interface. A mechanism of friction welding and an origin of embrittlement were discussed on the basis of the effects of heat treatments, on the hardness distribution changes of the joints and also on the fractographical features of tensile specimens.抄録全体を表示PDF形式でダウンロード (1345K) -
村田 眞1996 年 46 巻 12 号 p. 626-631
発行日: 1996年
公開日: 2007/03/30
ジャーナル フリーA new flexible type of tube bending method, based on the penetration bending, was invented by the author. It has been named the MOS bending method. Using the aforementioned bending method, tubes can be bent to the required bending radii by shifting the relative distance between the die and tube. The bending radius, the flattening of tube cross section and the bending forces are experimentally investigated as functions of the die bearing radius and the tube thickness using the MOS bending method and the results are summarized as follows, (1) The bending radius, flatness and bending forces had no effect on the die bearing radius. (2) The bending limit was extended, as the wall thickness increased. The relationship between the offset and the bending radius had little effect on the thickness. (3) The flatness in the wide direction decreased with increasing wall thickness, whereas the flatness in the radial direction was not affected by the wall thickness. (4) The penetration and bending forces increased, as the wall thickness increased.抄録全体を表示PDF形式でダウンロード (665K) -
嶋貫 宏泰, 長谷川 正, 安野 拓也, 高橋 徹, 西脇 信彦1996 年 46 巻 12 号 p. 632-637
発行日: 1996年
公開日: 2007/03/30
ジャーナル フリーAluminum–SiC particle composites (particle diameter: 0.4, 5μm; volume fraction: 0.6, 15%) were machined by dry turning using monocrystal diamond tools with different crystal orientation. In the (100) tool, the rake face was parallel to (010) plane and the direction of depth of cut was inclined by 5° from [100] toward [010]. The (110) tool was obtained by turning the (100) tool by 45° about [001] axis. Sharpness of cutting edge of the (100) tool was lost locally during machining because of large-scale chipping, the machined surface was quite rough. In the (110) tool, on the other hand, wear occurred nearly parallel to the rake and flank faces, and hence cutting edge was kept sharp. Although tool wear became more severe with increasing size and volume fraction of SiC particles, fine machined surface was obtained with this tool even in a composite with 15 vol%SiC particles of 5 μm in size. It is concluded that (110) tool is superior to (100) tool from a viewpoint of both tool wear and roughness of machined surface.抄録全体を表示PDF形式でダウンロード (1183K) -
小橋 真, 戸野倉 直道, 長 隆郎1996 年 46 巻 12 号 p. 638-643
発行日: 1996年
公開日: 2007/03/30
ジャーナル フリーThe spontaneous infiltration of BN-base powder mixture with molten aluminum was carried out to produce ceramic/metal composites. Ceramic phases were synthesized by the in situ reaction shown below. 2Al+2BN+Me→MeB2+2AlN where Me denotes a metal element (tantalum, niobium, zirconium or hafnium) . Each of these metal elements was mixed with BN powder. The spontaneous infiltration occurred in each system with a 3600 s holding at 1473 K, and neither pores nor cavities were observed in these specimens. After a 3600 s holding, TaB2 and NbB2 were completely formed together with AlN for [Ta, BN] and [Nb, BN] systems, respectively. These in situ formed particles were uniformly dispersed in aluminum matrix. In the case of [Zr, BN] and [Hf, BN] systems, however, residual MeB2 (Me: Zr or Hf) and BN were found. According to the differential thermal analysis, the heat of tantalum-aluminum and niobium-aluminum reactions, initiating at around 1200 K, can ignite a reaction including boron nitride. However, zirconium-aluminum and hafnium-aluminum reactions initiate at around 1000 K, and they do not ignite the reaction including BN. Hence, it took a longer processing time to complete the in situ reaction for specimens with [Zr, BN] and [Hf, BN] powder mixtures. The powder mixture of tantalum and boron nitride was infiltrated with molten aluminum at temperatures above 1173 K, and both tantalum boride and aluminum nitride were present as a result of the in situ reaction.抄録全体を表示PDF形式でダウンロード (1288K) -
大西 智, 平田 幸四郎, 鎌士 重晴, 小島 陽1996 年 46 巻 12 号 p. 644-649
発行日: 1996年
公開日: 2007/03/30
ジャーナル フリーThe fluidity of Mg–Al specimen has been investigated in order to establish semi-solid press-forming technology. The fluidity of strain-introduced specimen is much better than that of non-strained specimen leading to the microstructure with uniformly-distributed spherical particles. Fluidity during semi-solid press-forming of strain-introduced bulk increases with increase in the die temperature. But when injection speed is too high, porosity is easily generated because air bubbles are trapped into the specimen due to turbulent flow of semi-solid specimen. Too large particles gather in step section of die, resulting in the segregation of liquid phase.抄録全体を表示PDF形式でダウンロード (1488K) -
新川 貴啓, 影山 洋, 鎌士 重晴, 小島 陽1996 年 46 巻 12 号 p. 650-655
発行日: 1996年
公開日: 2007/03/30
ジャーナル フリーThe purpose of this study is to develop hybrid-reinforced Mg–4%Zn–0.2%Ca alloy matrix composites for an application to automobile engine piston. The alloy was squeeze-cast into composites using preforms with a volume fraction of 20% of hybridized aluminum boride whisker and alumina short fiber, and the effect of hybrid ratios, shapes and dimensions of the reinforcement materials on the structure and mechanical properties of the composites were investigated. Prediction of the tensile strength of the hybrid composites was also carried out by adding an increment of the strength due to an increment of dislocation density stemming from difference in the thermal expansion coefficient between the matrix and reinforcement materials to the strength calculated by using the conventional mixture rule. The reduction in tensile strength with temperature, which was serious in the composites reinforced with aluminum boride whisker, was suppressed by mixing alumina short fiber. As the hybrid ratio of aluminum boride whisker increased, tensile strength of the composites at room temperature increased, although the hardness peak in the aging curve became unclear and the age-hardenability decreased. The predicted tensile strength of the hybrid composites at room temperature was in good agreement with the experimental one.抄録全体を表示PDF形式でダウンロード (1263K) -
山下 雅弘, 坂根 幸治, 和田 英男, 原 卓男, 福永 秀春1996 年 46 巻 12 号 p. 656-661
発行日: 1996年
公開日: 2007/03/30
ジャーナル フリーThe conditions for solution and aging treatments of AC1A aluminum alloy reinforced with aluminum borate whiskers were investigated. When the composite was solution treated at 843 K for 100 ks, the whiskers reacted with AC1A and γ–Al2O3 was formed on the surfaces of the whiskers. At a lower temperature of 773 K, θ phase did not dissolve and no age hardening was obtained. On the other hand, the solution treatment at 788 K for 10 ks or longer dissolved these θ phase, resulting in age hardening. As an increase of aging time to 100 ks did not increase hardness, the temperature of 733 K and time of 10 ks are recommend for the conditions for solution treatment. It was found that surface reaction between the whiskers and AC1A did not reduced the amount of Cu in the alloy; thus this finding can explain the age hardening. In age hardening, the composite reached its highest hardness faster than the alloy, due to the acceleration effect in the composite for precipitation of θ' phase. The tensile strength of the composite showed a change with aging time similar to the hardness. The age treatment at 433 K for 72 ks resulted in the improvement of tensile strength to the similar extent to the alloy.抄録全体を表示PDF形式でダウンロード (883K)
連載講座
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高山 善匡1996 年 46 巻 12 号 p. 674-682
発行日: 1996年
公開日: 2022/02/15
ジャーナル フリーPDF形式でダウンロード (8694K)
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