商业纯镁的低频阻尼性能

采用机械动态分析仪测试纯度为99.96%纯镁的阻尼性能随应变振幅和温度的变化。测试的纯镁包括具有不同晶体学取向的商业镁合金铸锭CPM1和CPM2以及重新熔炼的等轴晶纯镁CPM。商业纯镁柱状晶粒的织构显著影响纯镁的阻尼性能,而重新熔炼的纯镁获得等轴晶,从而避免铸造织构对其阻尼性能测试结果产生的影响。结果表明：在阻尼应变谱中,等轴晶纯镁的阻尼性能明显高于有柱状晶织构的纯镁。对于三种纯镁,阻尼温度谱在80和230°C分别存在两个阻尼峰P1和P2,这两个阻尼峰分别是由位错与点缺陷交互作用以及晶界运动引起的。

Low frequency damping capacities of commercial pure magnesium

The amplitude-dependent and temperature-dependent low frequency damping capacities of magnesium with 99.96% purity were studied by a dynamic mechanical analyzer. The pure magnesium alloys include CPM1 and CPM2 castings having textures of columnar grains which extraordinarily influence the damping behaviours. The commercial pure magnesium alloy CPM was re-melted to obtain equiaxed grains, which could remove the effect of texture orientation on the damping behaviours of these pure magnesium alloys. The results of strain amplitude-dependent damping spectrums of these pure magnesium alloys show that the pure magnesium with equiaxed grains possesses the highest damping capacity. In temperature-dependent damping plot for all these three pure magnesium alloys, there are two damping peaks P1 and P2 located at 80 and 230 °C, respectively. These two damping peaks are considered to be caused by the interaction between dislocation and point defects, and the movement of grain boundaries, respectively.