1. State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha, China
2. College of Mechanical and Electrical Engineering, Central South University, Changsha, China
3. Light Alloys Research Institute, Central South University, Changsha, China
4. Technology Center, Yantai Wanlong Vaccum Metallurgy Co., LTD, Yantai, China
5. Electron Microscope Unit, University of New South Wales, Sydney, NSW, Australia