巻号一覧
52 巻, 8 号
選択された号の論文の7件中1～7を表示しています
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研究論文
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古井 光明, 川上 貴之, 佐治 重興, 箕田 正, 江崎 宏樹, 田中 宏樹, 吉田 英雄2002 年 52 巻 8 号 p. 339-345
発行日: 2002年
公開日: 2007/03/30
ジャーナル フリーGrain refinement by inducing large deformation strain at cryogenic temperature and then properly annealing, is an effective method to develop an aluminum alloy with high strength and high ductility. However, storage of deformation strain during rolling at the cryogenic temperature and its release behavior are not clear. In the present work, six kinds of samples; pure aluminum, Al–1.5 mass%Mn and Al–3 mass%Mg alloys with high purity and commercial purity, were rolled to 90% reduction in thickness, being dipped into liquid nitrogen bath. After the rolling, DSG curves of the deformed specimen were immediately measured from 93 to 573 K and from 293 to 773 K in two steps of measurement and hardness test was also carried out in the temperature range from about 100 to 295 K. Optical microstructure and EBSP observations were taken to confirm recovery and recrystallization processes. Release of the stored strain energy during heating starts at about 173 K and released amount of energy increases gradually with temperature to 573 K. The released amount of the stored strain energy during heating from 93 to 573 K is the largest in pure aluminum and it is followed in order of Al–1.5 mass%Mn and Al–3 mass%Mg alloys. The order of the released amount of the stored strain energy is the same order of the softening ratio with the rise in temperature from 93 to 293 K. On the specimens heated up to 573 K, a major region of pure aluminum shows recrystallization and a major region of the alloys is not recrystallized. The order of the released amount of the stored strain energy during heating from 573 to 773 K is reversed to that during heating from 93 to 573 K. The total released amount of the stored strain energy during heating from 93 to 773 K, during which recrystallization was finished in all specimens used, is the largest for the Al–3 mass%Mg alloy and followed in order of Al–1.5 mass%Mn alloy and pure aluminum. The total stored strain energy induced by rolling at cryogenic temperature is clarified to be larger than that induced by rolling at room temperature.抄録全体を表示PDF形式でダウンロード (486K) -
崎浜 秀和, 時末 光, 加藤 数良2002 年 52 巻 8 号 p. 346-351
発行日: 2002年
公開日: 2007/03/30
ジャーナル フリー5052 aluminum alloy used for substrate and consumable rod, was friction surfaced using a numerical controlled full automatic friction welding machine. Effects of the surfacing conditions on some characteristics of deposits were investigated. It was clearly observed that the circularly pattern appeared on the surface of deposit by the rotation of consumable rod. The deposit has a tendency to incline toward the right side further than center of deposit for the feed direction of consumable rod. This deviation accompanied the decrease of the rotational speed of consumable rod. The width of deposit increased with increasing friction pressure, and decreasing rotational speed of consumable rod. The thickness of deposit became thinner when the consumable rod was high revolution. The surfacing efficiency decreased with increasing friction pressure and rotational speed of consumable rod, but increased with increasing feed speed. Microstructure of the deposit was finer than that of the substrate and consumable rod. The softened area was recognized at 3 mm distance from the weld interface of substrate. The tensile strength of deposit increased with increasing friction pressure. The maximum tensile strength of deposits showed 88.8% of the base metal of substrate.抄録全体を表示PDF形式でダウンロード (522K) -
畑中 伸夫, 山口 克彦, 高倉 章雄, 飯塚 高志2002 年 52 巻 8 号 p. 352-358
発行日: 2002年
公開日: 2007/03/30
ジャーナル フリーGutting characteristics of an aluminum sheet (Al 100P–O) on an anvil by the penetration of a wedge shape punch is investigated. Numerical simulations of the cutting process are conducted using a rigid plastic finite element code developed by the authors. Various expressions of fracture initiation are used as fracture criteria and linked with the simulation. The deformation characteristics of the sheet and the cutting force are calculated in terms of nose angle and radius of the wedge shape punch. The applicability of the fracture criteria and the effects of nose angle and radius on the fracture value distribution are discussed on the basis of the calculated results. The simulation results for the various fracture criteria were almost same, except for the Glift fracture criterion. The simulation results show that the fracture value increases with punch penetration depth and the highest value appears at the edge of the punch. It is also predicted that when the punch penetration depth reaches about 80% of the sheet thickness the crack initiates at the edge of the punch. To confirm the results of the simulations, cutting experiments are carried out and the cutting mechanism is observed. The experimental results are qualitatively in good agreement with the simulation results.抄録全体を表示PDF形式でダウンロード (424K) -
平石 誠, 渡辺 健彦, 高野 格2002 年 52 巻 8 号 p. 359-364
発行日: 2002年
公開日: 2007/03/30
ジャーナル フリーThe press working of magnesium alloy sheet has been developed for the bodies of electric devices. To assemble a pressed magnesium products, studs are required to be built on them. In this study, we attempted to weld the stud 6 mm in diameter of AZ31B magnesium alloy to the AZ31B sheet 0.8 mm thick by stud welding, and compared the weldability between by using the Gap type and the Contact type method which were different in motion of the electrode and in the arc duration at welding. The following results were obtained in this study. Concerning the gap type, the joint strength decreased with decreasing accelerating distance of the stud. Under the condition that provided the sufficient joint strength of 1100 N or more, the fracture occurred in the sheet base metal. With the contact type, the joint strength increased with an increase in the thrust load of the stud. Upon lowering the thrust load to 100 N or less, the fracture occurred in the weld metal, where solidification cracks were recognized in parallel with the interface. The arc durations of 1.2 ms or less showed the high joint strength equivalent to the sheet base metal and the region of the arc duration was expanded to 1.7 ms by the use of Ar atmosphere.抄録全体を表示PDF形式でダウンロード (490K) -
菅藤 昭良, 田上 道弘, 白坂 康弘, 小田 裕介2002 年 52 巻 8 号 p. 365-370
発行日: 2002年
公開日: 2007/03/30
ジャーナル フリーAl–23%Si–6%Cu–1%Mg cast alloy composites containing dispersed graphite were prepared by means of die cast method to develop the wear resistance of bearings in boundary lubrication. An influence of graphite content and graphite particle size on the wear characteristics of the aluminum cast composites were investigated by the radial thrust test and the radial journal bearing test. As the results, the strength of composites decreased with increase in graphite contents, and consequently, the load carrying capacity of bearing showed lower value. The good wear resistance of bearings were obtained at the graphite contents of 6 to 8 vol% in composites. Furthermore the graphite particle size had more effect on improvement of the load carrying capacity of bearing. Higher the load carrying capacities of bearings were obtained at the conditions of composites containing 10 vol% dispersed graphite with particle sizes 0.85~0.42 mm and 0.42~0.25 mm for the radial thrust rubbing test.抄録全体を表示PDF形式でダウンロード (515K) -
武田 淳仁, 新家 光雄, 赤堀 俊和2002 年 52 巻 8 号 p. 371-377
発行日: 2002年
公開日: 2007/03/30
ジャーナル フリーRecently, Ti–4.5Al–3V–2Mo–2Fe, which is an alpha + beta type titanium alloy with excellent superplastic characteristics, has been developed for structural applications. In the case of using as aircraft materials, the fretting fatigue fracture, which is caused by the combination of cyclic fatigue stress and fretting, is highly expected. Microstructure of Ti–4.5Fe–3V–2Mo–2Fe is variously changed by heat treatments. Therefore, the effects of microstructures on fretting fatigue characteristics of the alloy conducted with various annealing treatments in alpha + beta field were investigated in this study. The fretting fatigue strength seems to be independent of microstructure in low cycle fretting fatigue life region. While, the fretting fatigue limit of the alloy tends to increase with decreasing area fraction and average diameter of primary alpha phase. However, when area fraction and average diameter of primary alpha phase are below certain values, the fretting fatigue limit is lowered by coarsening of acicular alpha phase, which precipitates in beta phase region.抄録全体を表示PDF形式でダウンロード (577K)
解説
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時末 光, 加藤 数良2002 年 52 巻 8 号 p. 378-383
発行日: 2002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 (592K)
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