of;
Advanced;
Material,;
University;
of;
Science;
and;
Technology;
Beijing,;
Beijing;
100083,;
China;
of;
Materials;
Science;
and;
Engineering,;
Chongqing;
University;
of;
Technology,;
Chongqing;
400050,;
China;
Kerun;
Lubricants;
Co.,;
Ltd.,;
Nanjing;
211100,;
China;
AZ91D镁合金; 纳米晶体; 热稳定性; 表面层; 场发射扫描电子显微镜; 晶粒长大激活能; 合金层; FESEM;