공정지도를 이용한 AA6082 합금의 연속 동적 재결정 및 고온 변형 거동 |
이상민, 이지운, 최현진, 현승균 |
인하대학교 신소재공학과 |
High Temperature Deformation and Continuous Dynamic Recrystallization Behaviors of AA6082 using Processing Maps |
Sang-Min Lee, Ji-Woon Lee, Hyun-Jin Choi, Soong-Keun Hyun |
Inha University, Division of Materials Science and Engineering, Incheon 22212, Republic of Korea |
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Received: 6 February 2016; Accepted: 10 May 2016. Published online: 5 November 2016. |
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ABSTRACT |
Torsion tests were performed on AA6082 samples to investigate their flow softening behavior and to determine optimum process conditions. Based on the experimental data and dynamic materials model, high strain processing maps were established which demonstrate the constitutive relationships among temperature, strain rate, strain and stress. The flow curves exhibited a single and smooth maximum, followed by a softening stage. Power dissipation efficiency increased with increasing deformation temperature, and decreased with increasing strain rate. The main softening mechanism was continuous dynamic recrystallization. The power dissipation efficiency could be divided into three stages. Two flow instability domains occurred. One was found at deformation temperatures ranging from 623 to 673 K. The other flow instability domain was found at deformation temperatures ranging from 673 to 773 K, and with strain rates ranging from 0.5 to 5/s at strains from 1.0 to 3.0, which were mainly located in the upper part of the processing maps. |
Keywords:
alloys, hot working, recrystallization, torsion test, processing map |
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