Synergistic effects of composition and heat treatment on microstructure and properties of vacuum die cast Al-Si-Mg-Mn alloys
- 22 Downloads
The purpose of this study was to prepare high-quality Al-Si-Mg-Mn alloy with a good combination of strength and ductility employing the vacuum-assisted high-pressure die cast process. An orthogonal study of heat treatments was conducted to design an optimized T6 heat treatment process for both AI-10%Si-0.3%Mg-Mn and AI-11%Si-0.6%Mg-Mn alloys. The results demonstrate that no obvious blisters and warpage were observed in these two alloys with solid solution treatment. After the optimal T6 heat treatment of 530°Cx3h + 165°Cx6h, AI-11%Si-0.6%Mg-Mn alloy has better mechanical properties, of which tensile strength, yield strength and elongation reached 377.3 MPa, 307.8 MPa and 9%, respectively. The improvement of mechanical properties can be attributed to the high density of needle-like β"(Mg5Si6) precipitation after aging treatment and the fine and spherical eutectic Si particles uniformly distributed in the α-AI matrix.
Keywordsheat treatment vacuum die casting Al-Si-Mg-Mn alloy microstructure mechanical properties
- Andersen S J, Zandbergen H W, Jansen J, et al. The crystal structure of the beta" phase in Al-Mg-Si alloys. Acta Materialia, 2007, 46(2): 3283–3298.Google Scholar