巻号一覧
50 巻, 2 号
選択された号の論文の5件中1～5を表示しています
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研究論文
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長海 博文2000 年 50 巻 2 号 p. 49-53
発行日: 2000年
公開日: 2007/03/30
ジャーナル フリーAn effect of Mg content on thermal properties such as latent heat, solidification range, specific heat and thermal conductivity at high temperature in Al–Mg alloys were investigated. In this study, to determine the solidification range of Al–Mg alloys, the values obtained by DSC test and specific heat test were compared with the ones obtained from equilibrium phase diagram. As a result, the specific heat test is considered to best for determining the solidification range. Furthermore, the relation between solid fraction and temperature was estimated by the curve of specific heat which was continuously measured during solidification. Main conclusions are shown below, (1) As the Mg contents increase the latent heat of fusion decreases and the solidification range becomes wide. (2) The solidification range can be accurately obtained from the curve of specific heat. (3) A method for estimating solid fraction of binary alloy has been established, and this method is able to apply to a multi-component system alloy.抄録全体を表示PDF形式でダウンロード (366K) -
城戸 孝聡, 佐藤 好生, 竹島 義雄2000 年 50 巻 2 号 p. 54-59
発行日: 2000年
公開日: 2007/03/30
ジャーナル フリーTo cope with the disarrangement of aluminum fins (called “Avec”) which occasionally occurs during the expansion process of copper tubes in the heat exchanger of room air conditioners, the effects of the mechanical properties, the thickness and the surface treatments of the aluminum fin stock on avec were investigated. These results are summarized as follows. (1) For avec, the compressive load on the fins at the unexpanded part of the heat exchanger, due to shrinking of the copper tube by the expansion, has a great influence on avec. When the compressive load on the fins is within the range for the fin shape, avec occurs. (2) The friction coefficient of the fin's surface treatment significantly affects the compressive load on the fins. By using a surface treatment having a very low friction coefficient, the compressive load can be sufficiently reduced to prevent avec. (3) The effect of the mechanical properties on avec have not been determined. The fin thickness has a small influence on avec. By using thicker fins, the occurrence of avec could be slightly reduced.抄録全体を表示PDF形式でダウンロード (656K) -
長田 直樹, 大年 和徳, 勝田 基嗣, 高橋 清造, 山田 正2000 年 50 巻 2 号 p. 60-64
発行日: 2000年
公開日: 2007/03/30
ジャーナル フリーThe AZ31 magnesium alloy sheet which showed the highest elongation among the magnesium alloy sheets was used. An examination of this alloy sheet was done if any influence was exerted on stretch tests that changes in annealing temperature were uniaxial and biaxial deformation. The way of making it changes to 623 K∼773 K and being cooled down went for annealing temperature in the oil quenching. The changes of 0.2% proof stress and tensile strength is not seen by cooling in oil by 723 K after heat-treating for 1 hour. However, stretch rose gradually in the test temperatures and decreased rapidly at 773 K. The n-value showed the transition point during the uniform deformation, and these values before and after the transition point showed higher values at 723 K. This trend was similar to those of elongation. As for the forming limit curve, a forming limit is extended and a relatively high value was exhibited. As for press forming, it is thus thought the thing it can be expected to get a high forming limit based on these results.抄録全体を表示PDF形式でダウンロード (514K) -
内海 能亜, 坂木 修次2000 年 50 巻 2 号 p. 65-69
発行日: 2000年
公開日: 2007/03/30
ジャーナル フリーIn the process of bending thin square tubes, undesirable phenomena can easily occur. These phenomena include flattening distortion of the cross-section, wrinkling on the compression region and splitting on the tension region. 6063 and 6061 aluminum extruded square tubes containing a center rib, having four kinds of thickness are applied to the rotary bending process. On the section of the square tube, a center rib arranged in the direction of radius of curvature is very effective in preventing splitting and increasing the limit of bending strain, and further, this rib has secondary effect to reduce flattening distortion and wrinkling. In this bending process, applying laminate elastic mandrel and additional axial tension to this workpiece can improve the working limits. As a result of this study, bend degree H0/R0 (where R0 is the radius of curvature on the central plane, H0 is the height of the square tube) reaches 0.33 without any defects in this bending process for the workpiece of 6063S–O with thickness ratio H0/t0 = 40.0.抄録全体を表示PDF形式でダウンロード (460K)
連載講座
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梅澤 修2000 年 50 巻 2 号 p. 86-93
発行日: 2000/02/28
公開日: 2021/06/30
ジャーナル フリーPDF形式でダウンロード (6652K)
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