- |<
- <
- 1
- >
- >|
-
鈴木 信行, 松本 夢史, 笹岡 修太, 徳弘 慧司, 竹内 修2017 年 67 巻 2 号 p. 35-40
発行日: 2017/02/28
公開日: 2017/03/30
ジャーナル フリーAn air intake lip skin of an aircraft jet engine nacelle wears a shape of shallow double cylinder. It is made of a sheet metal of the aluminum alloy, and is formed by spinning. On the other hand, die-less shear spinning technology has been developed recently, which can form the product using the elastomer of general purpose without using the mandrel. By applying this technology, it was attempted to build concentric double cylindrical shape of aluminum alloy sheet 5052, which was assuming the air intake lip skin. The bar tool of hemisphere tip is pressed into the effective depth against the blank sheet on the elastomer base which rotates on a lathe in this process. And it is driven to squeeze the flange plane around the product. Strain produced by this operation is independent of the sine law, it is possible to manufacture a cylindrical shape with a vertical wall. As a result, the concentric double cylinder shape for the purpose is built successfully, the deformation properties has been observed.
抄録全体を表示PDF形式でダウンロード (1102K) -
吉田 英雄, 渡辺 威郎, 八太 秀周2017 年 67 巻 2 号 p. 41-48
発行日: 2017/02/28
公開日: 2017/03/30
ジャーナル フリーThe effect of quenching rate on artificial age hardening in an Al–6.0% Zn–0.75% Mg alloy sheet was investigated by changing the quenching rate like water quenching (WQ), air cooling (AC) and furnace cooling (FC) followed by pre-aging at 20°C and then artificial aging at 120, 160 and 200°C. In pre-aging at 20°C for 10080 min, the quenching rate little influence the peak hardness at 120 and 160°C aging. However the peak hardness at 200°C aging of a sheet quenched by WQ and AC is lower than those quenched by FC regardless of the holding time at 20°C. In a long pre-aging at 20°C, many GP(I) zones are formed during pre-aging at 20°C even if the cooling rate is as slow as FC. These GP(I) zones transform into GP(II) ones which quickly transform into η′ phase during heating or aging. Therefore the strength of a sheet quenched by FC followed by 120 and 160°C aging is as high as those by WQ and AC. However these GP(I) and GP(II) zones dissolve by reversion during heating to 200°C. Therefore the strength of the sheet quenched by WQ and AC followed by 200°C aging decreases. On the other hand, it is considered that stable clusters or unknown GP zones form during FC, which did not dissolve up to 200°C and transform into η′. Therefore higher strength was obtained in FC at 200°C compared with WQ and AC.
抄録全体を表示PDF形式でダウンロード (1520K)
-
鈴木 貴晴, 久保田 剛, 橘内 透, 浅野 峰生, 高橋 一浩2017 年 67 巻 2 号 p. 50-56
発行日: 2017/02/28
公開日: 2017/05/30
ジャーナル フリーPDF形式でダウンロード (1724K)
- |<
- <
- 1
- >
- >|