钕对AZ91镁合金铸态组织的影响

Effect of neodymium on as-cast microstructure of AZ91 magnesium alloy

利用光学显微镜、电子探针和X射线衍射仪研究Nd对AZ91镁合金铸态显微组织的影响,并利用Imagetool软件测量晶粒尺寸和面积。结果表明:少量Nd对-αMg晶粒有显著的细化作用,平均晶粒尺寸由108μm降至约31μm,晶粒面积也明显减小,Nd的最佳加入量为0.5%。此外,Nd的加入致使-βMg17Al12相弥散细小,组织中出现了粒状或针状Al3Nd化合物。

Effect of neodymium addition on as-cast microstructure of AZ91 magnesium alloy was studied by optical microscope, electron probe microanalyzer and X-ray diffraction analyzer, the diameter and area of a-Mg grains were measured by image tool. The results show that a small amount of neodymium addition to AZgl magnesium alloy fines the α-Mg grains, the average grain size becomes 31μm from 108μm and the area of grain decreases obviously, the optimum content of Nd is 0.5%. With the addition of Nd, the amount of β-Mg17 Al12 phases decrease, and their size becomes dispersed and fine. In addition, the granular and needle-like Al3 Nd phases mainly distributed at grain boundaries are observed in the AZ91 alloys containing neodymium.