摘要
选择稍高于共晶反应温度作为等温热处理温度,对铸态Mg-15Gd-2Zn-0. 6Zr合金进行等温热处理,获得了半固态球化组织。研究了热处理温度和保温时间对半固态组织的影响,探讨了半固态组织演变机制及适用于低温等温热处理的半固态Mg-Gd-Zn-Zr合金成分设计。结果表明,液相组织具有低的温度敏感性,其组织演变主要机制为α-Mg表面熔化和α-Mg动态再析出,而固相颗粒球化机制为:α-Mg树枝晶→枝晶臂粗化→枝晶臂合并、不规则多边形化→球化。
Semi-solid spheroidized microstructure was obtained by isothermal treatment on as-cast Mg-15 Gd-2 Zn-0. 6 Zr alloy at the temperature slightly higher than eutectic temperature. The effects of isothermal heat treatment temperature and holding time on semi-solid microstructure were studied,and the mechanism of semi-solid microstructure evolution and the composition design of semi-solid Mg-Gd-Zn-Zr alloy were discussed. The results show that the volume fraction of liquid phase has a low sensitivity to temperature. The mechanism of the liquid phase evolution is α-Mg surface melting and α-Mg dynamic precipitation. And the spheroidization mechanism of solid phase particles is as follows: α-Mg dendritic→dendritic arm coarsening→dendritic arm merging and irregular polygonization→spheroidization.
作者
尹健
卢春辉
谢世坤
易荣喜
黄文先
Yin Jian;Lu Chunhui;Xie Shikun;Yi Rongxi;Huang Wenxian(School of Mechanical and Electrical Engineering,Jinggangshan University,Ji'an Jiangxi 343009,China;School of Aeronautical Manufacturing Engineering,Nanchang Hangkong University,Nanchang Jiangxi 330063,China;School of Building Engineering,Jinggangshan University,Ji'an Jiangxi 343009,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2020年第2期175-181,共7页
Heat Treatment of Metals
基金
国家自然科学基金(51661023)
江西省自然科学基金(20181BAB206028)
江西省教育厅科学技术研究项目(GJJ160732,GJJ160733)。
