Micro-mechanism of influence of pressure on equilibrium phase diagram of Mg-Al alloy system

摘要：

By using the empirical electron theory of solids and molecules (EET),the phase valence electron structure parameters of Mg 10% Al alloy melt are calculated.From the viewpoint of pressure effect on melt structure,the essential reason of deviation phenomenon for maximum solid solution point and eutectie point in equilibrium phase diagram is analysed.Moreover,this paper points out that under pressure condition,the change of equilibrium phase diagram is macroscopic reflection of the change of mierostructure information in alloy melt. The results show that: pressure function reduces diffusion rates of Al_12 residual bond structures in alloy melt,making them not easy to capture the other residual bond structures or wandering atoms around them,so the possibility of segregation is reduced greatly;Howev er,taking Mg atoms as a bridge,the dangling Al bonds will connect with Al_12 residual bond structures,forming the atomic clusters including Mg_17 Al_12 structures,which supplies effective crystal embryo spontaneously for forming β(Mg_17 Al_12)phase,and reduces the Al atom quantity in the Mg-Mg and Mg-Al atom clusters.

关键词： pressure Mg-Al alloy residual bond structure model melt structure non-equilibrium phase diagram

作者: MI Guangbao LI Peijie HE Liangju Wang Jing

作者单位: Advanced Materials International R & D Center,Tsinghua University,Beijing 100084,China School of Aerospace,Tsinghun University,Beijing 100084,China

会议类型: 国际会议

会议名称: The 10th China-Russia System on Advanced Materials and Technologies(第十届中俄新材料新工艺研讨会)

会议地点: 浙江嘉兴

会议语种:英文

页码: 199-204

在线出版日期: 2009-10-20（万方平台首次上网日期，不代表论文的发表时间）