AZ31镁合金压缩过程中织构对微观变形机制的影响

The effect of texture on micro-mechanism of AZ31 magnesium alloy during compression

摘要:

本文以AZ31镁合金热轧板材为研究对象，利用电子背散射衍射(EBSD)技术，研究了与板材法向(ND)分别成0°，30°，60°和90°的试样在室温压缩过程中织构对滑移和孪晶启动的影响。结果表明，0°试样有很高的屈服强度但无明显的屈服平台。拉伸孪晶的临界剪切应力(CRSS)比基面滑移的大。随着角度的增加，试样产生的{10-12}拉伸孪晶越来越多。0°试样由于很难发生拉伸孪晶，变形主要由滑移来完成，小角度晶界增加明显。柱面滑移的作用使得60°试样的小角度晶界明显高于30°试样的小角度晶界。

Abstract:

In this paper, the hot-rolled AZ31 Mg alloy sheet was chosen as studied project, the effect of texture on slip and twin activations of Mg alloy samples during compression at room temperature was studied by electron backscatter diffraction technique (EBSD). The samples, machined from the rolled Mg alloy sheet, were compressed with the compression axes tilted 0°，30°，60° and 90° from the sheet normal direction, respectively. A high yield stress, without distinct yield platform, is observed for the 0° samples. The critical resolved shear stress (CRSS) of extension twin is higher than that of basal slip. The number of {10-12} extension twin was increased gradually with the increase of the angle. The plastic deformation of the 0° samples are mainly performed by slips due to inactive tension twin, and low-angle boundaries increase obviously. There are more low-angle boundaries in the 60° samples than 30° samples because of the activation of prismatic slip.