中文摘要：

研究了机械振动处理技术对AZ91合金在消失模铸造条件下的组织形貌的影响，以及该铸态组织在半固态等温热处理过程中的组织演变，并探讨了振动细化机理和组织演变机理。结果表明：机械振动能显著地细化AZ91合金的铸态组织；在液固相区570℃等温处理时，其铸态组织都能由枝晶转变为球状晶组织，而且振动处理可获得更加细小并且均匀的球状组织。等温处理时间过长时，两种组织都会发生合并长大。

英文摘要：

Effect of mechanical vibration on microstructure of AZ91 alloy under lost foam casting and as_ast microstructure evolvement during semi-solid isothermal heat treatment has been researched with probing into mechanism of vibration fine and evolvement.Resulting in that mechanical vibration can markedly refine as_cast microstructure of AZ91 alloy,with 570 ℃ isothermal heat treatment of liquid_solid phase its dendrite can change into sphere crystal while more finer and even ones be obtained with vibration,however,overtime of isothermal heat treatment leading to combination and growing up of the both microstructure.