Al含量及热处理对挤压铸造Mg-Al-Zn合金组织和性能的影响

Effect of Al Content and Heat Treatment on Microstructure and Mechanical Properties of Squeeze Casting Mg-Al-Zn Alloy

研究了Al含量及固溶时效(T6)处理对挤压铸造Mg-Al-Zn合金显微组织和力学性能的影响。结果表明,晶界上的β-Mg17Al12相的体积分数随Al含量的增加而增加,其形态由孤岛状分布向不连续网状分布变化。当Al含量为8%时,合金具有最好的综合力学性能,经400℃×12 h固溶+200℃×8 h时效处理后,其抗拉强度和断裂伸长率达到了262.49 MPa和8.46%,相对挤压铸造态分别提高了16.07%和11.02%。

The effects of A1 content and heat treatment on the microstructure and mechanical properties of Mg-A1-Zn alloys were investigated. The results show that： as A1 content increasing, more 13-Mg-TAlx2 presents on the grain boundary, and the morphology changes from island to discontinuous network. The best mechanical properties are attained when A1 content is 8%, and after solution at 400 ℃ for 12 h and aging at 200 ℃ for 8 h, the ultimate tensile strength and elongation of the alloy respectively increase by 16.07% and 11.02%, reach 262.49MPa and 8.46%.