巻号一覧
60 巻, 9 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 9 号 p. 421-426
発行日: 2010/09/30
公開日: 2010/10/30
ジャーナル フリーThe purpose of this study is to produce AZ31 magnesium alloy strip with flat surface by melt drag process with forming roll and to reveal the effect of forming roll. Forming roll is equipped to experimental machine to form strip surface called free solidified surface on melt drag process. So we had researched about produced strip such as strip surface condition, strip thickness and microstructure. Forming roll formed strip surface partly and the formed area was flat. Too much apparent reduction induced strip surface cracks. Center of strip along strip thickness had refined microstructure. The crystal grain size is about 10 μm.抄録全体を表示PDF形式でダウンロード (4743K) -
世利 修美, 神山 裕行原稿種別: 研究論文
2010 年 60 巻 9 号 p. 427-432
発行日: 2010/09/30
公開日: 2010/10/30
ジャーナル フリーAluminum foil was dissolved in methanol with SiCl4 as a catalyst during several hours refluxing. After pH-controlled hydration (pH 7) by NH3 addition, white or light yellow precipitation powder was obtained when the solution has been parched in a drying oven. The existence of mullite was confirmed by XRD analysis after 1473 K and nine hours calcinations. The preparation of mullite was interpreted as corrosion product of aluminum corroded in methanol and its characteristics was explained as mixture of alumina with silica derived from SiCl4 via alkoxide formations.抄録全体を表示PDF形式でダウンロード (2445K) -
鹿川 隆廣, 伊藤 吾朗原稿種別: 研究論文
2010 年 60 巻 9 号 p. 433-437
発行日: 2010/09/30
公開日: 2010/10/30
ジャーナル フリーHydrogen in aluminum alloys frequently causes degradation of mechanical properties and surface quality of the products. Thus, the behavior of hydrogen in aluminum has been extensively studied. However, there has been an appreciable controversy in whether hydrogen intrudes the aluminum when exposed to air with moisture. In this study, hydrogen behavior in a pure aluminum foil that had been dehydrogenated and subsequently exposed to mainly air at temperatures ranging from room temperature to 550°C was analyzed by means of TDS, thermal desorption spectroscopy. In the specimens exposed to air and water at room temperature, hydrogen evolution was clearly observed at temperatures above about 450°C in the TDS spectra. This means that moisture at the specimen surface was converted to atomic hydrogen through the reaction with aluminum which subsequently diffuses into the specimen and is trapped by certain sites. Additionally, the specimens were annealed at several temperatures and humidities for 1 h. In the specimens exposed to air at different temperatures and humidity, the amount of hydrogen contained in the specimens was increased as the humidity and the temperature. Two peaks were seen at about 450 and 550°C in the spectra of the specimens containing large amount of hydrogen, and were found to correspond to the hydrogen trapped by dislocations and micro pores, respectively.抄録全体を表示PDF形式でダウンロード (621K) -
津田 峻輔, 吉原 正一郎, 辻 義貴, 入山 裕原稿種別: 研究論文
2010 年 60 巻 9 号 p. 438-443
発行日: 2010/09/30
公開日: 2010/10/30
ジャーナル フリーMagnesium alloys have several advantages which make them attractive for use in structural applications such as: high specific strength, ease of recycling and electromagnetic shield capabilities. There are, however, a few disadvantages associated with manufacture using magnesium alloys such as the fact that it is practically impossible to apply conventional metal forming techniques at room temperature without causing defects. In this study, a methodology of coating the surface of the alloy with a Diamond Like Carbon (DLC) coating in order to increase the surface lubrication is discussed. The DLC acts as a lubricant during the forming process, consequently it is easy to deform the workpiece. Friction tests and deep-drawing tests were carried out in order to estimate the effect of the DLC coating on the formability of the magnesium alloy. In both cases the performance of DLC-coated workpieces were compared to the performance of non coated workpieces using traditional lubricants. The friction tests were used to quantify the change in friction when using the DLC method. Deep-drawing tests were conducted at 200°C and the formability for each condition was measured at each temperature. It was concluded that the use of DLC-coated blanks produces an improvement in formability of magnesium alloys compared to more traditional lubrication techniques.抄録全体を表示PDF形式でダウンロード (2646K) -
高橋 知司, 南埜 宜俊, 小松 正雄原稿種別: 研究論文
2010 年 60 巻 9 号 p. 444-450
発行日: 2010/09/30
公開日: 2010/10/30
ジャーナル フリーThe interdiffusion in Ti-rich β Ti–Al–Fe alloys has been investigated in the temperature range from 1323 to 1473 K. The main interdiffusion coefficients, D˜TiAlAl and D˜TiFeFe, and cross interdiffusion coefficients, D˜TiAlFe and D˜TiFeAl, have positive values in the ternary alloys, and they have slight concentration dependence. The values of D˜TiFeFe are larger than those of D˜TiAlAl, D˜TiAlAl, and the values of D˜TiFeAl are also larger than those of D˜TiAlFe. The repulsive interactions exist between Al and Fe atoms in the Ti–Al–Fe alloys, because the ratio values of cross coefficient to main one are positive in sign. On the other hand, the interactions between Ti (solvent) and Al (or Fe) atoms are attractive in the present alloy, since the ratio of converted interdiffusion coefficients in the ternary alloys show negative values.抄録全体を表示PDF形式でダウンロード (723K) -
箕田 正, 吉田 英雄原稿種別: 研究論文
2010 年 60 巻 9 号 p. 451-457
発行日: 2010/09/30
公開日: 2010/10/30
ジャーナル フリーInfluences of cooling rates after homogenization heat treatment and heating temperatures of ingots before extrusion on thermal stability of fibrous structure of 2024 aluminum alloy extrusion after T4 temper was investigated. The thermal stability of the fibrous structure was influenced by both the main elements (copper and magnesium) and the transition element (manganese). The fibrous structure was stabilized when the solute atoms of copper, magnesium and manganese were increased by rapid cooling after the homogenization heat treatment and the extrusion temperature was close to the nose temperature of the manganese precipitation. Therefore, the thermal stability of the fibrous structure decreased when the copper and magnesium were not present or the manganese amount was reduced by half. Furthermore, the cooling rate and the heating temperature influenced the crystallographic texture of the extrusion. When the fibrous structure was stable, cube and brass texture tended to increase, while the copper texture tended to decrease in the F temper. The formation of the crystallographic texture was affected by recovery with precipitation of copper and magnesium during the extrusion process.抄録全体を表示PDF形式でダウンロード (8785K)
解説
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東 健司原稿種別: 解説
2010 年 60 巻 9 号 p. 458-466
発行日: 2010/09/30
公開日: 2010/12/30
ジャーナル フリーPDF形式でダウンロード (2610K)
連載講座
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大久保 喜正2010 年 60 巻 9 号 p. 467-474
発行日: 2010/09/30
公開日: 2023/01/30
ジャーナル フリーPDF形式でダウンロード (2321K)
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