AZ31镁合金的变形织构和协调变形机理

进行变形速率可控的单向拉伸试验,研究了变形织构与滑移和孪生等协调变形机理对AZ31镁合金综合性能的影响。结果表明:在沿挤压方向拉伸过程中,变形织构使{0002}晶面Schmid因子较低,基面滑移难以开动,屈服强度高。在沿45°拉伸过程中,变形织构使柱面取向晶粒处于发生{0002}滑移的最佳位置,基面取向晶粒的棱柱面滑移也处于最佳位置,屈服强度低而延伸率高。沿横向拉伸的力学性能主要受孪晶影响,由于大量孪晶诱发裂纹,延伸率最低。试样在45°和横向拉伸时产生的大量拉伸孪晶,是出现{0002}双峰织构的诱因。

Deforming Texture and Deformation Mechanism of Coordination of AZ31 Magnesium Alloy Sheets

The effects of deforming texture and deformation mechanisms of slip and twinning on the comprehensive performance of AZ31 magnesium alloy sheets were investigated by using uniaxial tensile test with controlled strain rate.The results show that the Schmid factor of {0002} basal plane is low, the slip of basal plane is difficult to start,and the yield strength is bigger along the tensile direction of extrusion.The grains of prismatic orientation lie in the best position for {0002} plane slipping,and the prismatic slip of the basal plane orientation also is in the best position.Therefore,the yield strength is low,and the elongation is bigger along the tensile direction of 45°.The twins have an important effect on the mechanical properties of the sheets,and the elongation is lower because the large numbers of twins induce crack along the transverse tensile direction.The large numbers of tensile twins are the inducement of producing the double peak texture of {0002} palne along the tensile direction of 45°and transverse direction.