Mg-10Gd-3Y-0.5Zr合金热压缩动态析出规律  

Characteristics of Dynamic Precipitation in Mg-10Gd-3Y-0.5Zr Alloys during Hot Deformation

作　　者：郑婷婷[1] 李德江[1] 曾小勤[1] 丁文江[1] 

机构地区：[1]上海交通大学材料科学与工程学院轻合金精密成型国家工程研究中心,上海200240

出　　处：《材料科学与工程学报》2016年第6期867-873,共7页Journal of Materials Science and Engineering

基　　金：国家自然科学基金资助项目(51171113;51301107);中国博士后科学基金资助项目(2012M511089;2013T60444)

摘　　要：本文定量地研究了Mg-10Gd-3Y-0.5Zr(GW103K)合金在350℃~450℃及10^(-4)s^(-1)~10^(-1)s^(-1)热压缩条件下的动态析出规律。结果表明:固溶处理后的合金在450℃下压缩时,晶内和晶界均无析出相产生,在350℃~400℃热压缩时,有大量不规则颗粒状的析出相产生;析出相主要是β相,平均成分为Mg5.5(Gd_(0.73)Y_(0.27)),大部分分布于再结晶小晶粒的晶界处;析出相的尺寸随温度升高和应变速率的降低而增大,400℃、10^(-4)s^(-1)变形条件下的析出相尺寸能达到1μm以上,而350℃、10^(-4)s^(-1)变形条件下的析出相尺寸在100nm左右;析出相的体积分数随应变量呈非线性增加。不同的变形条件下,析出相体积分数增长趋势不同。350℃下的析出相体积分数在应变量为1.10时达到了3.5%。热压缩过程中,动态析出阻碍位错运动,抑制再结晶晶粒长大,对细化再结晶晶粒起到重要作用。Dynamic precipitation behaviors were investigated in Mg-10Gd-3Y-0.5Zr alloys during compression at temperature range of 350-450℃ and strain rate range of 10-4-10（-4）s（-1）.It was found that there were massive irregular precipitates formed in the alloys when the deformation temperature is lower than 400℃.The precipitates were identified asβphase with an average composition of Mg5.5（Gd_（0.73）Y_（0.27））.Most precipitates were found forming along recrystallized grain boundaries.The size of the precipitates was increased with deformation temperature and decreased with strain rate.The volume fraction of the precipitates was increased nonlinearly with deformation strain while the increasing tendency was dependent on deformation temperature and strain rate.Dislocation slipping and recrystallized grain growth were probably inhibited effectively by dynamic precipitates during hot deformation.

关 键 词：MG-GD-Y-ZR镁合金 动态析出 热变形 定量统计 动态再结晶 

分 类 号：TG146.2[一般工业技术—材料科学与工程]