Partial melting and re-solidification in partially melted zone during gas tungsten arc welding of AZ91 cast alloy
During the welding of AZ91 cast alloy,the presence of eutectic β-Mg17Al12 phase results in constitutional liquation in the original interdendritic regions and in the formation of a partially melted zone (PMZ).In this study,gas tungsten arc welding (GTAW) and partial melting (simulated using furnace,salt bath and Gleeble) experiments were conducted.The results show that practically there would not be a critical heating rate during the welding to prevent constitutional liquation.The gradual change of the re-solidification microstructure within PMZ from base metal side to weld metal side was characterized.A sharp transition from base metal to PMZ has been observed.It is found that the original partially divorced eutectic has become a more regular eutectic in most of the PMZ,although close to the fusion boundary the re-solidified eutectic is again a more divorced one.Proceeding the eutectic re-solidification,α-Mg re-solidified with a cellular growth resulting in a serrated interface.The morphological change affected by the peak temperature and cooling rate will be presented and explained.
Mg cast alloy partial melting divorced and regular eutectic solidification
T.P.ZHU Z.W.CHEN W.GAO
Department of Chemical and Materials Engineering,University of Auckland,NZ Department of Mechanical and Production Engineering,Auckland University of Technology,New Zealand
国际会议
2007年国际有色金属大会(International Conference of Nonfereous Materials 2007)(ICNFM)
长沙
英文
2007-11-28（万方平台首次上网日期，不代表论文的发表时间）