平面应变压缩过程中初始取向对AZ31镁合金变形行为的影响

在室温和150℃下对AZ31镁合金进行平面应变压缩试验,应变速率为0.01 s-1,形变量为0.1.试样(切割于强织构的热轧板)的压缩轴c与其基面法向成不同的角度,从而研究初始织构对AZ31镁合金塑性变形行为的影响.利用电子背散射衍射花样(EBSD)采集变形试样的微观结构和织构信息,分析孪生和滑移行为.实验发现AZ31镁合金塑性变形由{10(-12)}<(-10)11>拉伸孪生和基面滑移共同控制,并确定了各种变形模式比例与晶体初始取向的关系,其中拉伸孪生在压缩轴垂直于c轴方向时占主导作用.

Effect of crystal orientation on the deformation behavior of the magnesium alloy AZ31 during plane strain compression

Plane strain (channel-die) compression tests have been carried out at room temperature and 150℃ on the magnesium alloy AZ31 up to a strain of ε =0.1 at a strain rate of 0.01 s-1. The effect of initial crystal orientation was examined by cutting samples from a highly textured hot-rolled sheet with the compression axis oriented at differing angles to the normal direction of the hot-rolled sheet. The microstmcture and texture of the deformed samples were characterized using the electron backscattered diffraction technique, and the information obtained used to analyze the twinning and slip activity. It was found that plastic deformation is controlled by a mixture of 10(-12)] < (-10)11 > extension twinning and basal plane alip. A continuous dependence of the contributions of each of these deformation modes on the initial crystal orientation was found, with extension twinning dominating in samples compressed perpendicular to the unit cell c-axis direction.