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_4C_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。
The effects of MnCO3 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 MnCO3 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 Al4C3andτ-AlMn phase can be generated from molten magnesium alloys modified by MnCO3,which exhibit multiple pairs of ORs with Mg as the potential nucleus of Mg grain.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2017年第4期427-431,共5页
Special Casting & Nonferrous Alloys
