摘要
研究了稀土元素Nd对AZ91D压铸态合金组织和性能的影响。试验结果表明,少量稀土元素Nd的加入,对提高AZ91D合金常温力学性能的作用较小,疏松、夹杂等组织缺陷是影响合金力学性能的重要因素;合金中加入少量的稀土元素Nd后所形成的Mg12Nd等高熔点化合物,可对合金晶粒起到钉扎作用,从而抑制晶界之间的滑移,阻碍位错的开动,有效地提高了合金的高温力学性能,与室温相比,150℃时合金的强度下降幅度仅为15%左右;合金在室温时表现为以解理断裂为主的脆性断裂,150℃拉伸时拉伸断口整体上表现为以韧性断裂为主的混合断裂。
Effects of Nd contents on microstructure and properties of die casting AZ91D alloy were investigated. It is found that mechanical properties of the AZ91D alloy at room temperature, which is closely dependent on the shrinkage porosity and impurity in the matrix, are slightly improved with a little Nd addition. However, elevated mechanical properties of the AZ91D alloy are greatly increased with a little Nd addition, which is attributed to formed Mg12Nd phase restraining the slipping of grain boundary and movement of dislocation by pining grain boundary, decreased by approximately 15% at 150℃ compared with ones at room temperature. Fracture mechanism of the alloy at room temperature is characterized by brittle cleavage fracture while it is characterized by ductile rupture at 150℃.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2009年第4期343-345,共3页
Special Casting & Nonferrous Alloys
基金
国家"十一五"科技支撑计划资助项目(2006BAE04B01)
关键词
镁合金
ND
压铸
Magnesium Alloy, Nd, Die Casting
