中、高应变速率下AZ80镁合金高温变形力学行为研究

文章通过对AZ80镁合金在不同变形温度和应变速率下的压缩实验,研究了其高温变形力学行为。讨论了中、高应变速率变形条件下,变形过程中试样温升对流变应力的影响,并进行了修正。将修正后的流变应力应用于合金挤压变形过程的数值模拟。结果表明,模拟挤压变形力与实测值接近,说明修正后的流变应力能很好地反映材料的变形力学行为。

On the flow stress behavior of AZ80 magnesium alloy compressed at high temperatures and medium/high strain rates

In the present study,hot compression tests of AZ80 magnesium alloy were performed on Gleeble 3500 at strain rates between 0.01s-1~50s-1 and deformation temperatures between 300℃~450℃.It was found that the flow stress increases with the decreasing of deformation temperature and increasing of strain rate.With the increasing of strain rate,deformation heating became more pronounced.Thus a correction of flow stress for deformation heating at medium/high strain rates was carried out.The corrected flow stress was introduced to a numerical simulation of hot extrusion process.Good agreements between the predicted and measured values in extrusion pressure were achieved.