巻号一覧
49 巻, 6 号
選択された号の論文の6件中1～6を表示しています
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研究論文
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北澤 君義1999 年 49 巻 6 号 p. 233-237
発行日: 1999年
公開日: 2007/03/30
ジャーナル フリーIn order to adapt to small-lot production of hole-flanged components, a process of rotary burring in which a blank is formed to fit on a tool-envelope surface made by relative motion of a tool around the blank, was proposed. Aluminum blanks were rotary-formed to hole-flanged components with various hole-diameters by means of the proposed burring operation, and the deformation behavior was examined experimentally. It is found that, by using a cylindrical tool with shoulder, the excess bending in the large clearance zone between the blank holder and the tool-envelope surface decreases with increasing of hole expanding ratio, so that the blank fits well with the tool-envelope surface. This result suggests that the proposed rotary burring method is suitable to adapt to small-lot production of the hole-flanged components. Furthermore, experimental results show that the values of the flange height agree well with those obtained by the uniform thickness model; the flange height is little affected by several conditions such as tool feed, work-hardening exponent and lubrication.抄録全体を表示PDF形式でダウンロード (1037K) -
奥村 善雄, 佐治 重興, 穴田 博1999 年 49 巻 6 号 p. 238-243
発行日: 1999年
公開日: 2007/03/30
ジャーナル フリーIn order to produce metal-matrix-composites by a simple method, it was attempted to fabricate Al/9.7 vol%Ti composite by pressing and by rolling after compression of alternately multilayered pure Al and Ti foils at room temperature. The formation process of Al/Ti composites was examined and tensile properties of the composites were measured. Tensile strength of the composites was compared with the values estimated from the rule of mixture on the flake reinforced composite. Joining of the multilayered Al/Ti foils is attained by nominal compressive stress from 0.5 to 2 GPa at room temperature. The obtained composites consist of dispersed Ti-flakes and Al matrix. The size of Ti-flakes becomes smaller with increasing compressive stress and reduction in cold rolling after compression. Nominal compressive stress of 1.0 GPa gives the highest tensile strength of the Al/Ti composites in the present work. Cold rolling with reduction of 70% after compression at 2 GPa gives lower tensile strength of the Al/ Ti composites than that without rolling.抄録全体を表示PDF形式でダウンロード (1308K) -
池野 進, 荒城 昌弘, 松田 健二, 品川 不二雄, 上谷 保裕1999 年 49 巻 6 号 p. 244-248
発行日: 1999年
公開日: 2007/03/30
ジャーナル フリーAging process of Al–1.0 mass% Mg2Si alloy composite materials with 4 vol% and 8 vol% Al2O3 particles was investigated by Vickers micro-hardness measurement and transmission electron microscope observation. When Al2O3 particles are dispersed into an Al–Mg–Si alloy, the age-hardenability was obviously lowered above at 473 K aging. The rectangular shaped spinels were observed at the interface between Al2O3 particles and the matrix. The overaged composite material with 4 vol% Al2O3 particles incluedes various kinds of metastable phase precipitates: namely β′ phase, the TYPE–B and TYPE–C precipitates of which crystal structures are different each other. Fraction of the three kinds of precipitates are the same as in the mother alloy containing 0.2 mass% excess Si. The composite material with 8 vol% Al2O3 particles contains the TYPE–A, TYPE–B and TYPE–C precipitates, but is free from β′ phase precipitates. The existence of those precipitates has correspondingly been observed in the mother alloy containing 0.4 mass% excess Si.抄録全体を表示PDF形式でダウンロード (1532K) -
高橋 明宏, 小林 俊郎, 戸田 裕之1999 年 49 巻 6 号 p. 249-252
発行日: 1999年
公開日: 2007/03/30
ジャーナル フリーThe measurement of ultrasonic wave velocity has been used to detect the delamination cracking during tensile tests in an 2091 T–8 Al–Li alloy at both liquid helium and room temperature. The measured stresses for initiation of delamination cracking are 335 and 357 MPa, for the cryogenic and room temperatures, respectively. The density of delamination cracks in the alloy is estimated from the observed reduction in ultrasonic wave velocity and resultant decrease in modulus of elasticity. It is estimated that the interfacial debonding strengths normal to a grain boundary are 116 and 113 MPa, for the cryogenic and room temperature, respectively. Fracture mechanics analysis has been used to estimate the onset of delamination cracking in the case of a cracked tensile specimen. The predicted levels of far field applied stresses are much lower than that for macroscopic crack initiation at both cryogenic and room temperatures, respectively.抄録全体を表示PDF形式でダウンロード (755K) -
箕田 正, 早川 秀哉, 吉田 英雄1999 年 49 巻 6 号 p. 253-257
発行日: 1999年
公開日: 2007/03/30
ジャーナル フリーA mechanism of pick-up formation on the surface of extrusions was discussed in this work. First, a quantitative evaluation method was established to determine the transformation ratio of α–AlFeSi (α ratio) from β–AlFeSi in 6063 aluminum alloy billets. By applying the integrated intensity technique of X-ray diffraction peak to study the effect of the α ratio on the pick-up formation, it became clear that the segregation zones in the billet surface affected the pick-up formation. When the α ratio at the billet surface was below 10%, heavy pick-up were observed on the extruded surface even though the α ratio was 100% at the billet center. In the surface of low α ratio billets, Mg2Si compounds existed around β–AlFeSi particles and it was observed that local melting occurred around them at a temperature between 570 and 580°C. Furthermore, pick-up defects were not found with low magnesium content billets although they showed the α ratio below 10% at the surface. Thus it was considered that pick-up defects occurred due to the peritectic reaction of Al, Mg2Si and β–AlFeSi at 576°C.抄録全体を表示PDF形式でダウンロード (1456K)
解説
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時末 光, 篠田 剛1999 年 49 巻 6 号 p. 258-262
発行日: 1999年
公開日: 2007/03/30
ジャーナル フリーPDF形式でダウンロード (1189K)
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