Effects of on-line solution and off-line heat treatment on microstructure and hardness of die-casting AZ91D alloy
The effects of on-line solution,off-line solution and aging heat treatment on microstructure and hardness of AZ91D die-casting alloy were investigated.Brinell hardness of die casting AZ91D alloy increases through on-line solution and off-line aging treatment but decreases after off-line solution treatment.By means of X-ray diffractometer,optical microscopy,differential thermal analysis,scanning electron microscope and X-ray energy dispersive spectroscopy,it is found that the microstructure of on-line solution and off-line aging AZ91D magnesium alloy die casting is similar to that of die casting AZ91D alloy that consist of α-Mg and β-Al12Mg17.The precipitation of Al element is prevented by on-line solution during solidification so that the effect of solid solution strengthening is enhanced.The β-Al12Mg17 phases dissolve in substructure and then precipitate along grain boundary after off-line aging treatment,and lead to microstructure refinement of AZ91D alloy so the effect of precipitation hardening is enhanced.The β-Al12Mg17 phases dissolve in substructure after off-line solution treatment and lead to grain boundary strengthening phase is reduced significantly and the hardness of die casting AZ91D is reduced.
Die casting magnesium alloy on-line solution off-solution treatment aging treatment
Xu Yulei Zhang Kui Li Xing-gang Lei Jian Yuan Haibo
State Key Laboratory for Fabrication and Processing of Nonferrous Metals, General Research Institute State Key Laboratory for Fabrication and Processing of Nonferrous Metals, General Research Institute Material Technology Institute of Commercial Vehicle Technical Center, Dongfeng Motor Co Ltd, Shiyan
国际会议
上海
英文
2-2
2012-10-19（万方平台首次上网日期，不代表论文的发表时间）