Effect of iron content and heat treatment on microstructure and mechanical properties of a recycled Al-Si-Mg aluminum alloy

The iron content is one of the most critical parameters affecting the microstructure and mechanical properties of recycled aluminum alloy. This study aimed to compare the microstructure and tensile properties of alloys with varying iron content to ascertain the optimal iron content for formulating a recycled Al-Si-Mg aluminum alloy. Additionally, the effects of aging temperature and aging time on the microstructure and mechanical properties of recycled aluminum alloy were investigated. With increasing aging temperature and time, both tensile strength and yield strength are improved, while elongation is decreased. Specifically, when subject to a heat treatment consisting of a solution treatment at 535 °C for 5 h followed by an aging treatment at 170 °C for 5.5 h, the newly designed recycled aluminum alloy achieves a tensile strength of 291 MPa and a yield strength of 238 MPa. These findings hold significant implications for the further development and broader application of recycled aluminum alloys.