Laboratory;
of;
Magnetic;
Levitation;
Technologies;
and;
Maglev;
Trains,;
Ministry;
of;
Education;
of;
China,;
and;
Superconductivity;
and;
New;
Energy;
R&
D;
Center,;
Southwest;
Jiaotong;
University,;
Chengdu;
610031,;
People’s;
Republic;
of;
China;
Superconducting;
Technologies;
Co.,;
Ltd.,;
Xi’an;
710018,;
People’s;
Republic;
of;
China;
Nb3Al; 机械合金化; 粉末冶金; 制备; 超导体; 相形成; X射线衍射; 表面自由能;