本文研究了铸态、固溶态和时效过程的Mg-1.67at.%Zn-2.3at.%Dy与Mg-1.51at.%Zn-2.77at.%Er合金的微观结构变化及其力学性能的影响。微观分析结果表明,Mg-1.67at.%Zn-2.3at.%Dy与Mg-1.51at.%Zn-2.77at.%Er合金,在493 K温度下时效20 h硬度均达到峰值,峰值硬度分别为106.4 HV和98.7 HV。拉伸试验结果表明,固溶处理后,合金Mg-1.67at.%Zn-2.3at.%Dy与Mg-1.51at.%Zn-2.77at.%Er的抗拉强度均有明显的提高。合金Mg-1.67at.%Zn-2.3at.%Dy固溶后包含三个相,分别是α-Mg相,Mg8Zn Dy共晶相,Mg12Zn Dy LPSO相(包括14H型和18R型)。合金Mg-1.51at.%Zn-2.77at.%Er固溶后包含三个相,分别是α-Mg相,Mg3Zn3Er2共晶相,Mg12Zn Er LPSO相(包括14H型和18R型)。
Based on crystallographic theory, there are 63 kinds of polytypes of 13H long-period stacking order （LPSO） structure, 126 kinds of polytypes of 14H LPSO structure, 120 kinds of polytypes of 39R LPSO structure, and 223 kinds of polytypes of 42R LPSO structure in a hexagonal close-packed （HCP） system, and their stacking sequences and space groups have been derived in detail. The result provides a theoretical explanation for the various polytypes of the LPSO structure.
Li YeDong-Shan ZhaoYuan-Lin ZhuangShuang-Feng JiaJia-Ping ZhouJia-Nian GuiJian-Bo Wang
