等温处理对挤压态AZ80A镁合金半固态组织的影响  

Effect of isothermal treatment on semi-solid microstructure of extruded AZ80A magnesium alloy

作　　者：段兴旺[1] 李鹏 李凯 Duan Xingwang;Li Peng;Li Kai(School of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan Shanxi 030024,China)

机构地区：[1]太原科技大学材料科学与工程学院,山西太原030024

出　　处：《金属热处理》2021年第10期39-44,共6页Heat Treatment of Metals

摘　　要：采用应变诱发熔化激活法(SIMA)工艺制备了AZ80A镁合金半固态坯料,研究了保温温度和保温时间对半固态组织的影响。结果表明:随着保温温度的升高和保温时间的增加,AZ80A镁合金的平均晶粒尺寸与液相率都呈上升趋势,形状因子呈先增大后减小的趋势。半固态组织由α-Mg晶粒、Al、Zn元素富集形成的晶界处液相和晶内“小液池”组成,其组织演变分为初始晶粒合并长大,晶粒球化、彼此分离,最终合并粗化3个阶段。采用该种方法制备AZ80A镁合金半固态坯料时合适的保温温度为550℃、保温时间为45 min,此时半固态组织的平均晶粒尺寸、形状因子和液相率分别为89μm、0.795和26.7%。AZ80A magnesium alloy semisolid billet was prepared by strain induced melting activation(SIMA)method,and the effects of holding temperature and holding time on the semi-solid microstructure were studied.The results show that the average grain size and liquid fraction of the AZ80A magnesium alloy increase with the increase of the holding temperature and holding time,and the shape factor increases first and then decreases.The semi-solid microstructure is composed ofα-Mg grains,liquid phase at grain boundary and intragranular“small liquid pools”formed by the enrichment of Al and Zn elements.The microstructure evolution can be divided into three stages:initial grain growth,grain spheroidization and separation,and finally grain coarsening.When using the SIMA method to prepare semi-solid AZ80A magnesium alloy,the suitable holding temperature is 550℃and the holding time is 45 min,by which the average grain size,shape factor and liquid fraction of the semi-solid microstructure are 89μm,0.795 and 26.7%,respectively.

关 键 词：AZ80A镁合金 半固态组织 保温温度 保温时间 组织演变。 

分 类 号：TG146.22[一般工业技术—材料科学与工程]