力学性能的影响
(1. 太原理工大学 材料科学与工程学院, 太原 030024；
2. 山西电力科学研究院, 太原 030001)
摘 要: 采用X射线衍射、 高分辨透射电镜等现代分析测试手段研究了AlP中间合金变质处理对AZ91+0.7%Si合金的显微组织和力学性能的影响。研究结果表明： AZ91+0.7%Si合金中加入一定量的Al-P中间合金变质处理后， Mg2Si的形貌发生了显著变化， 由汉字状变为细小的颗粒状， 其颗粒的平均尺寸为6~10 μm， 且基体组织的平均晶粒尺寸由原来的100 μm减小到45 μm左右， β-Mg17Al12相出现不同程度的断网，从而使AZ91+0.7%Si合金的力学性能得到显著提高。 说明Al-P中间合金对Si合金化的AZ91镁合金具有很好的变质强化功效， 是一种Mg2Si化合物的强化粒化剂。
关键字: 合金化AZ91; Mg2Si； 显微组织； Al-P中间合金； 变质处理； 力学性能
mechanical properties of Si alloying AZ91
magnesium alloys
（1. College of Materials Science and Engineering,
Taiyuan University of Technology, Taiyuan 030024, China;
2. Shanxi Electric Power Research Institute, Taiyuan 030001, China）
Abstract: The microstructures and mechanical properties of AZ91 containing 0.7% Si alloys modified by Al-P master alloy were observed using XRD and TEM. The results show that addition of certain amount Al-P master alloy into AZ91 containing 0.7% Si alloys leads to morphology change of Mg2Si phase from Chinese script to fine particle with the average particle size between 6 and 10 μm. The average grain size of the matrix reduces from 100 μm to 45 μm. The morphology of β-Mg17Al12 phase varys from continuous nets to discontinuous nets. Consequently, the mechanical properties of AZ91 containing 0.7% Si alloys are improved dramatically. It indicates that the Al-P master alloy has excellent modifying and strengthening effects on AZ91 containing 0.7% Si alloys and is a effective graining additive.
Key words: alloying AZ91; Mg2Si; microstructure; Al-P master alloy; modification; mechanical properties
