1. State Key Laboratory of Advanced Welding and Joining; Harbin Institute of Technology; Harbin 150001 China
2. Department of Physics and TcSUH; University of Houston; Houston TX 77204 USA
3. Department of Materials Science and Engineering; National University of Singapore; Singapore 117575 Singapore
4. Institute for Metallic Materials; IFW-Dresden; Dresden 01069 Germany
5. Department of Materials Science and Engineering; South University of Science and Technology of China; Shenzhen Guangdong 518055 China