中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 19 No. 5 October 2009 |
（1. School of Earth Science and Resources, Chang’an University, Xi’an 710054, China;
2. State Key Laboratory for Mechanical Behavior of Materials,
School of Materials Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China）
Abstract:Cu-Zn and Cu-Cr powders were milled with an attritor mill at room temperature, −10, −20 and −30 ℃, respectively. Phase transformation and morphology evolution of the alloyed powder were investigated by X-ray diffractometry(XRD), X-ray photoelectron spectroscopy(XPS) and scanning electron microscopy(SEM). The results show that lowering temperature can delay mechanical alloying(MA) process of Cu-Zn system with negative mixing enthalpy, and promote MA process of Cu-Cr system with positive mixing enthalpy. As for Cu-Cr and Cu-Zn powders milled at −10 ℃, lamellar structures are firstly formed, while fewer lamellar particles can be found when the powder is milled at −20 ℃. When the alloyed powder is annealed at 1 000 ℃, Cu(Cr) solid solution is decomposed and Cr precipitates from Cu matrix, whereas Cu(Zn) solid solution keeps stable.
Key words: Cu-Cr system; Cu-Zn system; mechanical alloying; phase transformation; mixing enthalpy
