巻号一覧
60 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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西田 進一, 本村 貢原稿種別: 研究論文
2010 年 60 巻 12 号 p. 625-628
発行日: 2010/12/30
公開日: 2011/01/30
ジャーナル フリーMagnesium alloy is the lightest structural material, so the market such as electrical device is increasing. The purpose of this study is to reveal the effect of superheat treatment for crystal grain size in melt drag process. Melt drag process is one of single roll strip casting process, and strip is made by molten metal directly. Superheat treatment temperature of molten metal are 750~1000, and superheat treatment time are 0~30 min. After superheat treatment, strip was casted by melt drag process. Crystal grain size, strip thickness and Vickers hardness were examined. Minimum crystal grain size is about 12 μm.抄録全体を表示PDF形式でダウンロード (3614K) -
古井 光明, 斉藤 俊祐, 砂田 聡, 池野 進, 才川 清二原稿種別: 研究論文
2010 年 60 巻 12 号 p. 629-634
発行日: 2010/12/30
公開日: 2011/01/30
ジャーナル フリーMagnesium alloys are remarkably corroded in chloride environments. The fundamental corrosion behavior of AM60 magnesium alloy cast into copper mold was investigated through a polarization test and electrochemical impedance spectroscopy. Metallographic characteristics were evaluated by optical microscopy using the sample in the conditions of as cast, as solution-treated and as aged. The solution-treated sample showed an excellent corrosion resistance because of its homogeneous microstructure. The other samples have poor corrosion resistance compared with the solution-treated sample. Cross sectional observation of the sample corroded under the constant quantity of electric charge revealed that inhomogeneity of microstructure advanced active dissolution of the pit bottom. The electrochemical characteristics for AM60 magnesium alloy related closely to their microstructure.抄録全体を表示PDF形式でダウンロード (2867K) -
木下 勝之, 小村 吉史, 大﨑 修平原稿種別: 研究論文
2010 年 60 巻 12 号 p. 635-640
発行日: 2010/12/30
公開日: 2011/01/30
ジャーナル フリーIn this study, the effects of specimen size and strain rate on the intergranular fracture of Si-rich 6000 aluminum alloy sheets were investigated by using tensile tests and by finite element analysis. The tensile tests were carried out by using specimens having two different sizes, two different (coarse and fine) grain sizes, and two types of excess Si under three different strain rates including a dynamic strain rate (10−1/s). With an increase in the strain rate and excess Si, the elongation decreased and the fracture mode of the intergranular fracture changed from ductile to brittle. The results of FEM analysis showed that the deformation of the grain boundary was restrained by the constraint effect of the plane strain. Therefore, the elongation of a specimen with a small aspect ratio of cross section increased as compared to that of a specimen with a large aspect ratio of cross section. The result of image analysis and the analysis of variance for the fracture surface showed that the strain rates are the most important factor determining the change of the intergranular fracture mode from ductile to brittle.抄録全体を表示PDF形式でダウンロード (3284K) -
畑中 伸夫, 松浦 規夫, 飯塚 高志, 高倉 章雄, 山口 克彦原稿種別: 研究論文
2010 年 60 巻 12 号 p. 641-646
発行日: 2010/12/30
公開日: 2011/01/30
ジャーナル フリーA new process for friction aided deep drawing has been developed in which a metal blank holder divided into four segments is used instead of the elastic ring normally employed in punchless drawing. This blank holding device consists of four drawing segments, which can move radially inwards and outwards depending on the blank holding pressure. The drawing process can be efficiently performed using an assistant punch, which partially supports the deformation of the b1ank as well as improving the shape and dimensional accuracy of the drawn cup. The blank is rotated around the punch following every second drawing step to achieve a uniform thickness distribution of the product sidewalls. Deep drawing experiments have been carried out using soft aluminum sheets 0.5 mm in thickness to clarify the details of blank deformation and metal flow in the proposed drawing process. The potential of the proposed process has been confirmed by successfully producing deep cups with a drawing ratio of 4.0.抄録全体を表示PDF形式でダウンロード (2386K) -
大野 卓哉, 久保田 正広原稿種別: 研究論文
2010 年 60 巻 12 号 p. 647-653
発行日: 2010/12/30
公開日: 2011/01/30
ジャーナル フリーEffect of the mechanical milling conditions on hardness and constituent phase of pure titanium was investigated. The mechanical milling atmosphere and amounts of stearic acid, added as a process control agent (PCA), were varied. The hardness of mechanically milled (MMed) pure titanium powders in the air atmosphere was approximately 15% higher than that in the argon atmosphere. The mean particle size of the MMed powders in the air atmosphere was smaller compared to that in the argon atmosphere. The MMed pure titanium powders produced by two different atmospheres had almost the same constituent phase. The MMed powders were consolidated into bulk materials by spark plasma sintering (SPS). The hardness of the SPS materials produced from the MMed powder in the air atmosphere was 13% higher than that in the argon atmosphere. The amount of oxygen in the SPS materials significantly increased by the MM processing in the air atmosphere. The mean grain size of the SPS materials showed approximately 1 μm. The SPS materials were mainly strengthened by both solution hardening of oxygen and grain refinements.抄録全体を表示PDF形式でダウンロード (2333K) -
青木 翔, 久保田 正広原稿種別: 研究論文
2010 年 60 巻 12 号 p. 654-659
発行日: 2010/12/30
公開日: 2011/01/30
ジャーナル フリーIn order to fabricate Mg-based composite powders possessing magnetic properties, pure magnesium and Ni–Cu–Zn ferrite powders were mechanically alloyed (MAed) using a vibrational ball mill. Change in Vickers microhardness of the pure magnesium powders as a function of the mechanical milling (MM) times obeyed the Hall–Petch relation. Change in Vickers microhardness of the composite powders as a function of the amount of Ni–Cu–Zn ferrite obeyed the rule of mixture when the MA time was 2 h. On the other hands, a slope of Vickers microhardness of the composite powders as a function of the amount of Ni–Cu–Zn ferrite was higher than that of a theoretical value calculated from the rule of mixture when the MA time was 4 h and 8 h. Magnetization of the composite powders obeyed the amount of the Ni–Cu–Zn ferrite powder, whereas no systematic change for coercive force was observed. Mg-based composite powders exhibiting magnetic properties were successfully produced by mechanical alloying.抄録全体を表示PDF形式でダウンロード (5798K)
解説
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矢吹 彰広原稿種別: 解説
2010 年 60 巻 12 号 p. 660-665
発行日: 2010/12/30
公開日: 2011/03/30
ジャーナル フリーPDF形式でダウンロード (3298K)
連載講座
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井上 博史2010 年 60 巻 12 号 p. 666-675
発行日: 2010/12/30
公開日: 2023/01/30
ジャーナル フリーPDF形式でダウンロード (2800K)
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