1. Shanxi Key Laboratory of Metal Forming Theory and Technology, School of Material Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, Shanxi, P. R. China
2. Technology Center, Taiyuan Iron & Steel (Group) Co., Taiyuan 030003, Shanxi, P. R. China
3. Department of Electronic Science and Engineering, Key Laboratory of Photo-Electronic Thin Film Device and Technology of Tianjin, Nankai University, Tianjin 300350, P. R. China