Mg-Al-Zn-Si耐热镁合金Mg_2Si相形貌及其对力学性能的影响

Morphology of Mg_2Si Particles and Its Effects on Tensile Properties of Mg-Al-Zn-Si Alloy

采用金相显微镜、X射线衍射仪、性能测试等分析测试手段,研究了Mg-Al-Zn-Si耐热镁合金中Mg2Si相的形貌及其对力学性能的影响。结果表明,当合金中添加少量的Si元素后,Mg2Si相以汉字状形貌存在;当Si含量增多时,开始出现多边形形貌的Mg2Si,且其含量随着Si含量的增多而增多,同时汉字状Mg2Si减少。多边形Mg2Si不利于合金的力学性能,其体积分数越高,合金的力学性能下降幅度越大。合金中Al含量越高,越容易抑制汉字状Mg2Si的生长,并促进多边形Mg2Si的生成。Mg2Si相由汉字状转化为多边形的临界区域,Al和Si元素的含量呈现一定的线性关系。

Morphology of Mg2Si particles and its effects on the microstructure and tensile properties of Mg-Al-Zn-Si alloys were investigated using optical microscopy,XRD analysis and tensile test.The experiment results show that Chinese script type Mg2Si particles formed when a small addition of Si is added.And polygonal shaped Mg2Si particles precipitate and increase with increasing the Si content.However,more Si addition leads to more polygonal type Mg2Si particles,and results in the reduction of tensile properties.There is a linear relationship between the amount of Si addition and the amount of Al addition in the critical transition zone of Chinese script type Mg2Si particles and polygonal type Mg2Si particles.