摘要
Gadolinium (Gd) solubility in magnesium (Mg) matrix and precipitate composition in Mg-Gd binary alloys were investigated. The alloys containing different Gd contents (10 wt.%-35 wt.%) were employed to identify Gd solubility after annealing at different temperatures. It was confirmed that the maximum Gd solubility was 22.8 wt.% at 550 ℃based on the regression analysis method. Mg5+xGd (0〈x〈2) and Mg3Gd precipitates coexisted in all investigated alloys owing to the strong component segregation during solidification. The fraction of Mg5+xGd (0〈x〈2) was decreased with the increment of annealing temperature and time. In contrast, Mg3Gd precipitate could not be elimi- nated even when being annealed at 550℃. This thermal stable precipitate played a significant role in mechanical properties. Therefore, it is very necessary to consider the effect of Mg3Gd precipitate on properties of Mg-Gd based alloys in future.
Gadolinium (Gd) solubility in magnesium (Mg) matrix and precipitate composition in Mg-Gd binary alloys were investigated. The alloys containing different Gd contents (10 wt.%-35 wt.%) were employed to identify Gd solubility after annealing at different temperatures. It was confirmed that the maximum Gd solubility was 22.8 wt.% at 550 ℃based on the regression analysis method. Mg5+xGd (0〈x〈2) and Mg3Gd precipitates coexisted in all investigated alloys owing to the strong component segregation during solidification. The fraction of Mg5+xGd (0〈x〈2) was decreased with the increment of annealing temperature and time. In contrast, Mg3Gd precipitate could not be elimi- nated even when being annealed at 550℃. This thermal stable precipitate played a significant role in mechanical properties. Therefore, it is very necessary to consider the effect of Mg3Gd precipitate on properties of Mg-Gd based alloys in future.
基金
Project supported by National Natural Scientific Foundation of China(51101142,50821001)
Postdoctoral Science Foundation(2012M510766)