Grain refinement and mechanical characteristics at elevated temperatures in 7475 aluminum alloy sheets.
スポンサーリンク
概要
- 論文の詳細を見る
The effects of testing temperature, imposed strain rate, heating rate up to testing temperature and holding time before stretching on the total plastic strain have been investigated in warm-rolled 7475 aluminum alloy sheets. The value of strain rate sensitivity parameter, m, (=∂lnσ/∂lnε) and apparent activation energy for plastic flow were also measured. Mechanical characteristic and optical microscopic observations showed that in order to take large superplastic elongation the specimens should be heated quickly up to the optimum testing temperature and be stretched just before the advent of static recrystallization. The value of m was about 0.2 in the range of temperature from 583 to 650K, however, it increased with increasing temperature and reached about 0.55 above 770K. The apparent activation energy for plastic flow was 358kJ/mol in the temperature range of superplastic flow. Compensating by the change in grain size and elastic modulus at testing temperature, the activation energy reduced to 160kJ/mol. This suggests that the grain accommodation during superplastic flow is controlled by the bulk diffusion.
- 一般社団法人 軽金属学会の論文
一般社団法人 軽金属学会 | 論文
- Mechanical and wear properties of SiC whisker/ADC12 aluminum alloy composites fabricated by die casting.
- Joining of aluminum and ceramics.
- タイトル無し
- Undercooling and solidification behavior of fluid clumps of second-poured melt of hypereutectic Al-Si alloy in Duplex Casting process.
- Change in apparent viscosity of stirred slurry during production of semi-solid hypereutectic Al-Si alloy by slurry-melt mixing process.