AZ31镁合金不同温度挤压后组织性能研究

Mechanical Properties of AZ31 Mg Alloy Extruded at Different Die Temperatures

摘要:

研究不同模具温度挤压变形对细晶AZ31镁合金力学性能和织构演变的影响。结果表明，挤压变形显著地细化AZ31镁合金的晶粒，大幅度地提高了材料的抗拉强度和屈服强度，而材料的延伸率变化不大。室温挤压时，材料的抗拉强度和屈服强度分别为322和233 MPa，延伸率为21%。随着模具温度的升高，变形后材料组织中的大角度晶界所占的比例逐渐变大，表明挤压过程中的动态再结晶越来越充分。挤压变形后，形成{0002}基面环形织构，织构强度较原始状态显著减弱。通过综合分析材料的力学性能以及织构分布，发现AZ31镁合金的力学性能

Abstract:

The mechanical properties and texture evolution of AZ31 Mg alloy extruded at different die temperatures are investigated in this paper. It is found that the grains of alloy are refined after extrusion. The tensile strength and yield strength are significantly enhanced, but the elongation is not increased notablely. The tensile strength, yield strength and elongation of the sample extruded at 20 ℃ are 322 MPa, 233 MPa and 21%, respectively. The frequencies of high angle grain boundaries of the as-extruded samples are raised with increasing the extrusion temperatures, which indicates that the dynamic recrystallization is more and more sufficient. The basal ring type texture has been formed in the as-extruded samples, and a significant decrease in the intensity of basal ring type texture is detected. Our study reveals that the mechanical properties of AZ31 Mg alloy are not only related with the average grain size, but also with the texture.