等温热处理对AZ91D＋Ce镁合金半固态组织的影响  

Effect of Isothermal Heat Treatment on the Microstructure of Semi-solid AZ91D+Ce Magnesium Alloy

作　　者：胡勇[1] 饶丽[1] 黎秋萍[1] 万强[1] 

机构地区：[1]华东交通大学载运工具与装备教育部重点实验室,江西南昌330013

出　　处：《稀有金属材料与工程》2016年第2期493-497,共5页Rare Metal Materials and Engineering

基　　金：载运工具与装备省部共建教育部重点实验室项目(华东交通大学);江西省钨铜新材料重点实验室开放基金项目(2013-KLP-07)

摘　　要：研究了等温热处理对AZ91D+Ce镁合金半固态组织的影响,获得了较理想的球状或类球状晶粒组织。结果表明,在等温热处理的过程中,加入稀土Ce会阻碍原子向固相粒子聚集和结合,抑制固相颗粒的长大,形成细小圆整的半固态组织。随等温热处理温度的升高,原子活动能力增强,熔化速度加快,液相量增加,固相颗粒尺寸先减小后增大。在等温初始阶段,熔化对初生固相颗粒尺寸起决定作用,使得颗粒尺寸减小。但是,随等温时间的进一步增加,由于合并粗化和Ostwald熟化的作用,固相颗粒开始长大。The effect of isothermal heat treatment on the microstructure of semi-solid AZ91D＋Ce magnesium alloy was investigated and the ideal globular and near-globular microstructure was obtained. The results show that the rare earth Ce can hinder aggregating and associating of the primary solid particles, inhibit growing of the solid particles and form fine well-distributed round semi-solid microstructure. At higher isothermal heat treatment temperature, there is more liquid phase due to the stronger movability of atoms and faster melting rate of solid particles. The size of solid particles is decreased first and then increased. The size of solid particles is mainly decided by melting in the initial stage of isothermal heat treatment. Therefore, the size of solid particles is decreased. However, with further increasing of the isothermal heat treatment time, the size of solid particles is mainly decided by a coarsening mechanism and Ostwald ripening; therefore, the size of solid particles is increased.

关 键 词：等温热处理 AZ91D+Ce镁合金 半固态 

分 类 号：TG146.21[一般工业技术—材料科学与工程]