中國有色金屬學(xué)報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 17 Special 1 November 2007 |
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Zhengzhou Research Institute of CHALCO, Zhengzhou 450041, China）
Abstract:The microstructures and tensile properties of Mg-9Gd-3Y-0.3Zr alloys were investigated by OM, SEM and mechanical property tester. The results show that the microstructure of as-cast sample is a typical dendritic structure, the grain size of extruded sample is finer than that of the as-cast because of recrystallization. The aging response of extruded specimens is quick and marked when the samples are aged at 200 to 250 ℃ for different time, and the peak aging hardness is about HV120. The tensile strengths at 25, 200, 250 and 300 ℃ are 375, 364, 329 and 286 MPa, respectively. The maximum elongation is higher than 18% at 300 ℃. The fracture mode is mainly microvoid coalescence fracture combining with brittle cleavage fracture at room temperature, and microvoid coalescence fracture at 250−300 ℃.
Key words: magnesium alloy; rare earth; aging treatment; tensile property
