The Effect Of RE Elements On Inheritance To Microstructure And Property Of Die Casting Mg Alloy

In recently years , with the mass appliance of magnesium alloy , There are more and more factories manufacture magnesium alloy . But there are also many problems in manufacture and research , Though it is identical composition in different factories , the organization capability of produced cast have different performance. , it has heredity relations with their foregoing materials . It can also be found the same phenomena in the produced return furnace materials . It is a imperative problem that how to eliminate the heredity phenomena of the raw materials and the return furnace materials to ensure produce can be processed stably. By the means of add the rare earth to magnesium alloy, This paper discuss the heredity influence of the rare earth to magnesium alloy organization and capability. (1) The rare earth can change the casting magnesium alloy's organization's heredity capability., the rare earth has influence to AZ91D\AM60B magnesium alloy's organization and heredity; when the rare earth be added with 0.5 percent , the organization heredity capability is still existed , with more and more added quantity , this heredity capability will be destroyed , when the added quantity is 1.5 percent, AZ91D\AM60B magnesium alloy organization heredity capability vanish completely . (2) The rare earth can improve the casting magnesium alloy's heredity capability ,when add the less rare earth , the cast which be produced in the same factory and material has approached capability , but it is a much bigger difference between the different factories, when add the rare earth with 1.5 percent , this phenomena vanish. the chapped character of the chapped part is the comparative trend. There are identical characters between AZ91D and AM60B casting magnesium alloy. (3) RE affects the heredity to microstructure and property of magnesium alloy because RE is a kind of active element. The interior energy of interface can decrease, the number of crystal nucleus increase, through adding RE. And a layer adsorbing film blocking the grain growing and fining grain come forth on the surface of depositing phase or growing phase. At the same time the possibility of short range order atom group as crystal nucleus growing to grain reduce ,so does the possibility of heredity to microstructure.