热速处理对AZ70镁合金显微组织和力学性能的影响  

Effect of Thermal-Rate Treatment on Microstructure and Mechanical Properties of AZ70 Magnesium Alloys

作　　者：陈晶阳[1] 王利国[1] 关绍康[1] 林敦文[1] 

机构地区：[1]郑州大学材料科学与工程学院,河南郑州450002

出　　处：《铸造》2005年第10期963-966,共4页Foundry

基　　金：河南省科技攻关资助项目(0224360015);河南省高校创新人才工程资助项目(豫2001-6)。

摘　　要：研究了热速处理对AZ70镁合金显微组织和力学性能的影响。结果表明:热速处理能使合金的铸态组织和晶粒尺寸得到显著细化,AZ70合金的优化热速处理工艺为:过热温度(Ts)=850℃,激冷速度(Vc)=2.0℃/s,此时,合金的平均晶粒尺寸从140μm细化到45μm,铸态合金的显微硬度、抗拉强度和屈服强度分别比未热速处理合金提高10.4%、18.1%和38.9%,冲击吸收功为未热速处理合金的2.16倍,具有良好的综合力学性能。经过热速处理的合金在固溶温度下,原子扩散速度加快,β-Mg17Al12(Tm=437℃)相易于固溶。The effect of thermal-rate treatment （TRT） on microstructure and mechanical properties of AZ70 magnesium alloys was studied. The results showed that the as-cast microstructure and the grain size were refined remarkably after TRT. The optimized TRT technics was Ts （superheat-temperature）=850 ℃ and Vo（chilling rate）=2.0 ℃/s, respectively. The average grain size decreased from 140 μm to 45 μ m. The microhardness, tensile strength and yield strength were 10.4%, 18.1% and 38.9% higher than that of alloy without TRT. And the ,energy to fracture was 2.16 times that of alloy without TRT. The diffusion rate of atoms in the alloy after TRT at the temperature of solid solution （410 ℃） was faster than that without TRT. Therefore the 15-Mg17Al12（Tm=437 ℃） phase was easy to solution.

关 键 词：AZ70镁合金 热速处理 显微组织 力学性能 

分 类 号：TG113[金属学及工艺—物理冶金]