5083铝合金在400℃的超塑性变形行为和硬化特征

摘要

To investigate the superplasticity of 5083 aluminum alloy below 500 ℃, constant-strain-rate tensile tests were performed at 400 ℃. The strain hardening exponent n and strain rate sensitivity index m were obtained. And the influence of strain rate on elongation δ, n and m was analyzed. The results indicate that the maximum elongation of 5083 aluminum alloy at 400 ℃ was 278% at constant strain rate 0. 000 26 s-1, n=0.122 and m=0.274. The increase of strain rate caused n decreasing and peak values of δ and m. The effect of ε on δ was obvious.%为研究5083铝合金在500℃以下的超塑性,在400℃进行了恒应变速率拉伸试验,获得了应变硬化指数n及应变速率敏感性指数m,分析了应变速率ε对伸长率δ,n和m值的影响.结果表明:在400℃时5083铝合金可获得的最大伸长率为278%,对应的ε=0.000 26 s-1,n=0.122,m=0.274;n随应变速率增大而减小,δ和m随应变速率增大先增大后减小,其中δ受应变速率影响显著.