时效处理对Mg-Nd-Zn-Zr合金组织的影响  

Effect of Aging Treatment on Microstructure Evolution of Mg-Nd-Zn-Zr Alloy

作　　者：马少博 何伟[2] 陈利超 赵莉萍 MA Shao-bo;HE Wei;CHEN Li-chao;ZHAO Li-ping(Inner Mongolia University of Science&Technology,Baotou 014010,China;State Key Laboratory Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization,Baotou Research Institute of Rare Earths,Baotou 014030,China)

机构地区：[1]内蒙古科技大学,内蒙古包头014010 [2]包头稀土研究院白云鄂博稀土资源研究与综合利用国家重点实验室,内蒙古包头014030

出　　处：《稀土》2020年第4期111-118,共8页Chinese Rare Earths

基　　金：国家自然科学基金项目(59493300);国家重点研发计划项目(2016YFB0101205);教育部博士点基金项目(9800462)。

摘　　要：为研究时效处理对Mg-Nd-Zn-Zr合金组织的影响,在540℃进行固溶处理保温8 h,在200℃进行时效处理,时效时间分别为10 min、30 min、1 h、2 h、4 h、8 h、16 h、24 h、72 h、240 h、480 h。对合金显微组织进行分析,研究其与时效处理后合金的析出物和硬度的关系。经研究发现,Mg-Nd-Zn-Zr合金的铸态组织中晶粒为等轴状,第二相呈网状分布。经固溶处理后,第二相向内溶解,网状断开。再经200℃时效处理,第二相(β′)原位析出致其更加均匀,使其硬度明显提高。β′相的析出速率呈现先升高后下降的趋势,在时效处理2 h^4 h时硬度达到峰值。到达峰时效后β′相开始向β相转化,β′相为主要合金强化相。The effect of aging treatment on Mg-Nd-Zn-Zr alloy was investigated.The alloy was solution treated at 540℃for 8 h and agd at 200℃for 10 min,30 min,1 h,2 h,4 h,8 h,16 h,24 h,72 h,240 h and 480 h,respectively.The relationship between precipitates and hardness was elucidated,The results show that the as-cast alloy consists of equiaxed grains and net second phases.After solution treatment,the second phases dissolve into grains with disconnected net.β′phase precipitated after aging at 200℃,which improved hardness obviously.Precipitation rate increased firstly and then decreased,the peak hardness was obtained after aging for 2 h^4 h.β′phase which act as dominant hardening precipitates was transformed intoβphase after peak-age.

关 键 词：Mg-Nd-Zn-Zr合金 时效处理 析出相 

分 类 号：TG146.45[一般工业技术—材料科学与工程]