采用应变速率循环法、恒速度法、恒应变速率法, 在450, 475, 500 ℃下分别对切割面粗糙度不同的5083铝合金进行拉伸, 研究了温度、拉伸方式、切割面粗糙度对其超塑性的影响以及应变速率循环法拉伸后的显微组织。结果表明: 5083铝合金经上述三种方式拉伸后, 其最大伸长率分别为131%, 108%, 149%, 分别对应最佳变形温度为475 ℃, 500 ℃, 500 ℃, 而且线切割面粗糙试样的伸长率均低于线切割面光滑试样的; 在应变速率循环法拉伸时, 随着变形温度的升高, 5083铝合金的原始长条状组织逐渐断裂并变短, 最后变成等轴组织。

The 5083 aluminum alloy specimens with different roughnesses of cutting surface were tested on a tensile tester using the strain rate cycling method, the constant strain rate method and the constant velocity method at 450,475 ℃ and 500 ℃. The influences of temperature, tensile methods and roughness of cutting surface on the superplasticity of the alloy as well as the microstructure of the alloy after tensile test in strain rate cycling method were studied. The results show that the optimal elongations of the 5083 aluminum alloy through the three tensile methods were respectively 131% at 475 ℃, 108% at 500 ℃, and 145% at 500 ℃. And the elongations of the samples with rough surface were much less than those of the samples with smooth cutting surface. In the strain rate cycling method tensile test, the original strip structure of 5083 aluminum alloy began to fracture and tended to be shorter, and eventually became an equiaxed structure with the increase of deformation temperature.