Duan Siyi, Liu Sheng, Zhang Shichang. Grain Refinement Mechanism of Cast Mg-Al Alloys with MnCO3 Additions[J]. Special Casting & Nonferrous Alloys, 2017,37(4):427-431. DOI: 10.15980/j.tzzz.2017.04.023.
MnCO3细化Mg-Al系铸造合金晶粒的机理
摘要
在Mg-Al合金熔体中添加MnCO
3
细化剂
研究了MnCO
3
对铸造Mg-Al系合金晶粒尺寸的影响
并运用"边-边匹配"模型结合热力学与微观组织的分析
探讨了其细化机制。结果表明
MnCO
3
对铸造Mg-Al合金晶粒有明显的细化作用
且对AZ31合金的细化效果最好。通过"边-边匹配"模型计算及热力学分析可知
经MnCO
3
变质后
镁液中有可能生成Al
4
C
3
、τ-AlMn化合物
这些化合物与Mg有多对晶体学位向关系
可以作为α-Mg的有效形核质点。
Abstract
The effects of MnCO
3
addition on grain size of the cast Mg-Al alloys were investigated by adding the refiner into the melt
and the refinement mechanism was described by using the edge-to-edge matching model combined with thermodynamics and microstructure analysis.It can be found that MnCO
3
has significant refining effect on grain size in as-cast Mg-Al alloys
especially for AZ31 alloy.Based on calculation of the edge-to-edge matching model and thermodynamics analysis of microstructure
the Al
4
C
3
andτ-AlMn phase can be generated from molten magnesium alloys modified by MnCO
3
which exhibit multiple pairs of ORs with Mg as the potential nucleus of Mg grain.
关键词
镁合金MnCO3晶粒细化边-边匹配模型
Keywords
Mg AlloysMnCO3Grain RefinementEdge to Edge Matching Model