等温时间对自孕育法制备Mg-9Zn-2Al镁合金半固态浆料的影响  

Effect of Isothermal Time on Mg-9Zn-2Al Magnesium Alloy Semi-Solid Slurry Prepared by Self-Inoculation Method

作　　者：李春[1] 李元东[2] 周春生[1] 刘彦峰[1] 袁训峰[1] 常亮亮[1] 

机构地区：[1]商洛学院,陕西商洛726000 [2]兰州理工大学,甘肃兰州730050

出　　处：《中国铸造装备与技术》2013年第4期28-32,共5页China Foundry Machinery & Technology

基　　金：商洛学院博士启动基金资助项目(12SKY01-1)

摘　　要：采用自孕育法在线制备Mg-9Zn-2Al镁合金半固态浆料，研究了等温温度为585℃时，等温时间对Mg-9Zn-2Al镁合金半固态组织演变的影响。结果表明，随着保温时间的延长，晶粒先球化而后恶化，并且不断长大，保温4～8min时，其晶粒较好，尺寸为65～72μm，圆整度在1．2～1．3之间。在此过程中，组织的演变主要经历高熔质点相的析出及较小过冷度下的瞬态形核、镁原子堆积促使初生相的长大和a相的合并长大三个阶段。Semi-solid slurry of Mg-9Zn-2A1 magnesium alloy has been prepared online by self-inoculation method（SIM）. The effect of isothermal time on semi-solid microstructure evolution has been investigated with isothermal temperature 585℃. Results showed that with isothermal time prolonging, the grain has been with a process of firstly being spheroidized and then mutilated and continuous to grow. An ideal isothermal time should be limited to 4-8rain for average grain size of 47.5-48.8~m with roundness between 1.2 and 1.3. In isothermal process, Microstructure evolution mainly had three stages including high melting particle precipitation and transient nucleation at smaller undercooling, and grains continuous growing because of magnesium atoms cumulation on the primary phase, and coalescence and growing of α phase.

关 键 词：等温时间 半固态浆料 Mg-9Zn-2Al镁合金 自孕育法 

分 类 号：TG249.9[金属学及工艺—铸造]