中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 19 No. 1 February 2009 |
（1. College of Materials Science and Engineering, Chongqing Institute of Technology, Chongqing 400050, China;
2. College of Materials Science and Engineering, Chongqing University, Chongqing 400030, China）
Abstract:The microstructure of semi-solid isothermal heat-treated AZ61-0.7Si magnesium alloy was investigated, and compared with that of the Sb-modified AZ61-0.7Si alloy. The results indicate that it is possible to produce the AZ61-0.7Si alloy with a non-dendritic microstructure by semi-solid isothermal heat treatment, and adding 0.4% Sb can accelerate the non-dendritic microstructural evolution of the alloy. After being treated at 580 ℃ for 120 min, the Sb-modified AZ61-0.7Si alloys can obtain a non-dendritic microstructure with a higher liquid content (16%−18%) and finer unmelted primary solid particles (43−53 μm) compared with the alloy without Sb modification. In addition, after being treated at 580 ℃ for 120 min, the Mg2Si phases in the AZ61-0.7Si alloys with and without Sb modification change from initial Chinese script shape to granule and/or polygon shapes.
Key words: magnesium alloy; AZ61-0.7Si alloy; semi-solid isothermal heat treatment; Mg2Si phase; Sb
