1. State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals Department of Materials Science and Engineering Lanzhou University of Technology Lanzhou 730050 P. R. China
2. State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University Xi'an 710049 P. R. China
3. School of Energy Engineering Huanghuai University Zhumadian Henan 463000 P. R. China