等温热处理对Mg-7Zn-0.3Li-xNd合金组织的影响  

Effect of isothermal heat treatment on microstructure of Mg-7Zn-0.3Li-xNd alloy

作　　者：黄晓锋[1,2] 张鑫涛 陶伟 贺光亮 陈宣宇 何丹丹 HUANG Xiaofeng;ZHANG Xintao;TAO Wei;HE Guangliang;CHEN Xuanyu;HE Dandan(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China;Key Laboratory of Nonferrous Metal Alloys and Processing,Ministry of Education,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,兰州730050 [2]兰州理工大学有色金属合金及加工教育部重点实验室,兰州730050

出　　处：《中国有色金属学报》2024年第10期3325-3338,共14页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(51971105)。

摘　　要：使用等温热处理法对不同Nd含量的Mg-7Zn-0.3Li-xNd合金(x=0.1, 0.3, 0.5, 0.7)进行不同温度不同保温时间的热处理,研究保温温度与保温时间对Mg-7Zn-0.3Li-xNd合金非枝晶组织演变规律的影响,分析非枝晶颗粒的形成机理。结果表明:Mg-7Zn-0.3Li-0.5Nd合金在580℃保温30 min后得到理想的球状非枝晶颗粒,其固相率、平均晶粒尺寸和形状因子分别为71.9%、47μm和1.85。随着保温温度的增加或保温时间的延长,非枝晶颗粒的平均晶粒尺寸和形状因子呈现先降低后升高的趋势,固相率则持续降低。随着温度和时间的变化,非枝晶组织的演变过程主要分为三部分:枝晶的粗化,分离与球化,合并与熟化。The isothermal heat treatment(SSIT)was used to treat Mg-7Zn-0.3Li-xNd alloys with different Nd contents(x=0.1,0.3,0.5,0.7)at different temperatures and holding time.The influences of holding temperature and holding time on the evolution of non-dendrite microstructure in Mg-7Zn-0.3Li-xNd alloys were studied,and the formation mechanism of non-dendrite particles was analyzed.The results show that Mg-7Zn-0.3Li-0.5Nd alloy obtains ideal spherical non-dendrite particles held at 580℃for 30 min,with solid phase ratio,average grain size,and shape factor of 71.9%,47μm and 1.85,respectively.With the increase of holding temperature or the extension of holding time,the average grain size and shape factor of non-dendrite particles reveal a trend of first decreasing and then increasing,while the solid content continues to decrease.With the changes of temperature and time,the evolution process of non-dendrite structure can be mainly divided into three parts,namely dendrite coarsening,separation and spheroidization,and merging and maturation.

关 键 词：Mg-7Zn-0.3Li-xNd 等温热处理 半固态 非枝晶组织 

分 类 号：TG146.21[一般工业技术—材料科学与工程]