高钆耐热镁合金在高温蠕变过程中的显微组织演变  

Microstructural Evolution of High Gadolinium Heat Resistant Magnesium Alloys during High Temperature Creep

作　　者：付三玲 李全安 张清 Fu Sanling;Li Quanan;Zhang Qing(College of Physics and Engineering,Henan University of Science and Technology,Luoyang 471023,China;School of Materials Science and Engineering,Henan University of Science and Technology,Collaborative Innovation Center of Nonferrous Metals,Luoyang 471023,China)

机构地区：[1]河南科技大学物理工程学院,河南洛阳471023 [2]河南科技大学材料科学与工程学院,有色金属共性技术河南省协同创新中心,河南洛阳471023

出　　处：《中国稀土学报》2020年第5期655-660,I0003,共7页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(51571084,51171059)资助;河南科技大学博士科研启动基金项目(13480050)资助。

摘　　要：以时效态Mg-12Gd-3Y-1Sm-0.5Zr (%,质量分数)合金为研究对象,利用蠕变持久试验机在250℃/50 MPa下对合金的蠕变性能进行了测试,并采用TEM研究了合金在250℃/50 MPa下蠕变10, 30 min, 100 h过程中的显微组织和相的演变。结果表明:时效态Mg-12Gd-3Y-1Sm-0.5Zr合金相由α-Mg基体和β′相组成,β′相为纳米析出相,在高温蠕变过程中,晶内析出相明显长大,形貌由黑色椭圆形颗粒向菱形和长条状转变,经对应的选区电子衍射谱标定,相结构未发生变化;晶界上析出相粗化,转化为平衡相β相。本研究为开发高温高强抗蠕变耐热镁合金提供理论基础。The aging Mg-12 Gd-3 Y-1 Sm-0.5 Zr(%, mass fraction) alloy was taken as the research object in this paper. The creep property of the alloy was tested with a creep endurance tester at 250 ℃/50 MPa. The microstructure and phase evolution of the alloy during creep at 250 ℃/50 MPa for 10, 30 min and 100 h respectively were studied by transmission electron microscope(TEM). The results showed that the aging Mg-12 Gd-3 Y-1 Sm-0.5 Zr alloy phase are composed of α-Mg matrix and a β′ phase. The β′ phase is a nano-precipitated phase. During the high-temperature creep process, the precipitated phase grows significantly and its morphology changes from black oval particles to diamond and long bar. The precipitated phase on the grain boundary coarsens into the equilibrium β phase. This study provides a theoretical basis for the development of high-temperature, high-strength, creep resistant and heat-resistant magnesium alloys.

关 键 词：Mg-Gd-Y-Sm-Zr 显微组织 透射电镜 高温蠕变 

分 类 号：TG166.4[金属学及工艺—热处理]