预变形镁合金轧板的低温时效及对力学性能的影响

Low-temperature Aging and Its Effects on Mechanical Properties of Rolled Magnesium Alloys with Prestrain

将没有预先变形的Mg-6Al-1Zn镁合金轧板置于170℃退火10 h,发现该温度下退火对材料力学性能几乎没有影响。作为比较,将Mg-6Al-1Zn镁合金轧板沿轧制方向进行预压缩,产生拉伸孪晶。随后,将带有孪生片层的样品在170℃下进行时效处理。发现第二相粒子的析出优先发生在孪晶和孪晶界。析出相为Al 12 Mg 17。由于孪晶和孪晶界面的析出,材料沿同一方向重新加载时,屈服应力明显增加。

A rolled Mg-6Al-1Zn magnesium alloy without pre-strain was annealed at 170℃for 10 h.It was found that the annealing had little effect on mechanical properties.As a comparison,a rolled Mg-6Al-1Zn alloy was pre-compressed along rolled direction to generate tensile twins.Afterward,the samples containing twin lamellas were annealed at 170℃for aging.Precipitation of the second-phase particles was found to occur in twins and twin boundaries.The precipitation phase was proved to be Al 12 Mg 17.Because of the precipitation of the second phase,yield stress increased obviously when compressed along the same direction.