Transactions of Nonferrous Metals Society of China
JOURNAL OF RAILWAY SCIENCE AND ENGINEERING
|Vol. 17 No. 5 October 2007|
（1. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China; 2. Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100080, China;3. International Centre for Materials Physics, Chinese Academy of Sciences, Shenyang 110016, China; 4. Beijing General Research Institute for Nonferrous Metals, Beijing 100088, China ）
Abstract:The nanocrystalline Al-Zn-Mg-Cu alloy powders were synthesized using cryomilling. Deformation twins and twinning at ambient temperature were observed in Al-Zn-Mg-Cu powders. Experimental results indicate that high strain rate at low temperature during cryomilling induces the formation of deformation twins by the climbing of the restricted dislocations in nano-scale grains, and the cryomilled powders at high energies and nonequilibrium state reduce the grain boundary energies by twinning.
Key words: cryomilling; Al-Zn-Mg-Cu alloy; twins; mechanism