中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 21 No. 3 March 2011 |
（1. Shanghai Key Laboratory of D&A for Metallic Functional Materials,
School of Material Science and Engineering, Tongji University, Shanghai 200092, China;
2. National Power Traction Key Laboratory, Southwest Jiaotong University, Chengdu 610031, China）
Abstract:The effects of microstructural characteristics on the fatigue behavior in Al-Si-Mg alloy were investigated. The dislocation substructures of Al-Si-Mg alloy were observed by transmission electron microscopy (TEM). Dislocation evolution process of α(Al) matrix with [011] orientation of Al-Si-Mg alloy specimens was observed during fatigue process under different stress amplitudes and cycles. The results indicate that dislocation structure is closely dependent on stress amplitudes, and the density of dislocation in failure specimens increases with increasing stress amplitudes. The results show that Mg2Si and secondary silicon phase could have a strong hindrance effect on the movement of dislocations during the fatigue process. The fatigue behavior is strongly dependent on the microstructure of material.
Key words: Al-Si-Mg alloy; dislocation; Mg2Si; secondary silicon phase
