热处理对挤压铸造Mg93YZn6合金组织和性能的影响

Effects of High Temperature Heat Treatment on Microstructure and Properties of Squeeze Casting Mg93YZn6 Magnesium Alloy

采用挤压铸造法制备了Mg93YZn6合金,并对其进行高温热处理,分析了铸态和热处理态的Mg93YZn6合金的微观组织、显微硬度和力学性能。结果表明,该合金的挤压铸造和热处理后的组织中均只有α-Mg基体相和准晶I相生成。经500℃×4h热处理后,合金中的准晶相含量与铸态合金中变化不大。经550℃×2h热处理后,合金中的准晶相有所减少。与铸态合金相比,热处理后合金的硬度、抗拉强度和伸长率均提高。

Mg93YZn6 alloy was prepared by squeeze casting,and then it was treated by heat treatment at high temperature.The microstructure,microhardness and mechanical properties of the as-cast and heat-treated Mg93YZn6 alloy were analyzed by OM,SEM and tensile testing.The results reveal that theα-Mg matrix and the qusaicrystal I-phase are generated in the microstructure after squeeze casting and heat treatment.After heat treatment at 500℃for 4 h,the content of quasicrystal phase can be ignored for change in the as-cast alloy.The quasicrystal phase is decreased after heat treatment at 550℃for 2 h.Compared with those of the as-cast alloy,the hardness,tensile strength and elongation of the alloy are all improved,especially elongation after heat treatment.