AZ31镁合金大压下率轧制条件下组织与性能

Microstructure and properties of AZ31 magnesium alloy under high pressure rolling

热轧态AZ31镁合金板材进行单道次大变形异步轧制,对轧制后的镁合金板材进行显微组织、力学性能分析。研究结果表明,随着压下率的增大,板材的晶粒得到显著细化,压下率为36.4%时,晶粒从10.9μm细化至3.8μm。随着晶粒的细化,抗拉强度逐渐提高,伸长率则呈线性下降,含有较多孪晶时,合金在变形时容易在材料内部形成裂纹源,使塑性降低。

The microstructure of AZ31 magnesium alloy after synchronous rolling with single-pass large deformation was studied.One strip of secondary asynchronous rolling with pressing rates of 23.7%,30.5%and 36.4%.With the increase of the pressing rate,the grain of the plate was significantly refined.When the pressing rate was 36.4%,the grain was refined from 10.9μm to 3.8μm,and the microstructure of the hot-rolled sheet was not uniform.It was composed of three different grains:coarse grain,small dynamic recrystallization new grain and twin.The causes of microstructure changes were analyzed.