中文摘要：

借助光学显微镜和JEM-2000FX透射电子显微镜（配备OXFORD ISIS EDXS附件）等分析手段,研究了AlP变质Si合金化ZA84合金的组织及力学性能。结果表明,ZA84合金、Si合金化ZA84（S1）合金及AlP变质Si合金化ZA84（P01）合金经固溶处理后,其Mg2Si及τ相的尖锐棱角变钝。ZA84合金的峰值时效时间在2 h,其纳米级的析出相沿基体α-Mg的（0001）密排面的[1010]晶向析出,而S1及P01合金的峰值时效时间推迟至8 h左右,其纳米级的析出相无取向分布。合金的析出机制均为连续析出。ZA84合金通过Si合金化、AlP对组织的变质和细化以及合金热处理,其力学性能得到了显著提高。

英文摘要：

The microstructure and mechanical properties of AlP-modification ZA84 magnesium alloy containing silicon were investigated using optical microscopy and JEM-2000FX transmission electron microscopy equipped with OXFORD ISIS EDXS.The results show that as compared to the as-cast,the edges and corners of phases Mg2Si and τ are polished in ZA84 alloy,silicon alloyed ZA84 alloy（S1）and AlP-modification ZA84 alloy containing silicon（P01）after solid solution treatment.The peak-value aging time is 2 h for ZA84 alloy and 8 h or so for S1 and P01 alloys.The nanometer-size particles precipitate along the ／direction on（0001）plane of α-Mg in ZA84 alloy,while in S1 and P01 alloys along random directions.The precipitation is by continuous manner during aging of the alloys.The mechanical properties of ZA84 alloy is improved markedly by silicon alloying,AlP modification and heat treatment.