| Title： | Effect of solution treatment on microstructure and mechanical properties of as-cast Al-12Si-4Cu- 2Ni-0.8Mg-0.2Gd alloy | |
| Author： | Yu-dong Sui1, 2, Ye-hua Jiang1, and *Qu-dong Wang2 | |
| Address： | 1. School of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093, China; 2. National Engineering Research Center of Light Alloys Net Forming and State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, Shanghai 200240, China | |
| Key words： | Al-Si-Cu-Ni-Mg alloy; Gd element; solution treatment; microstructure; mechanical properties | |
| CLC Nmuber： | TG146.21 | |
| Document Code： | A | |
| Article ID： | 1672-6421(2022)03-238-07 | |
| Abstract： |
Effect of solution treatment on microstructure and mechanical properties of Al-12Si-4Cu-2Ni-0.8Mg-0.2Gd alloy was investigated. Results show the Si particles become stable and more intermetallic compounds dissolve in the matrix after solution treatment at 500 °C for 2 h followed by 540 °C for 3 h (T4). The skeleton-like Al3CuNi develops into two parts in the T4 alloy: one is Al3CuNi which has the framework shape; the other is intermetallics including the Al3CuNi (size: 5-10 μm) and AlSiCuNiGd phases (size: ≤5 μm) with complex structure. Adding 0.2% Gd can improve the mechanical properties of the alloys after two-step solution treatment (500 °C/2 h followed by 540 °C/3 h), the hardness of the alloy increases from 130.9 HV to 135.8 HV compared with the alloy with one-step solution treatment (500 °C/2 h), the engineering strength increases from 335.45 MPa to 352.03 MPa and the fracture engineering strain increases from 1.44% to 1.67%.
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