Study on Heat Treatment Process of Al–6.5Si–3.5Cu Alloy by Orthogonal Test

The influence of solution time, aging temperature and aging time on the tensile properties of Al–6.5Si–3.5Cu alloy was studied by orthogonal test. The results show that aging temperature is the most important factor affecting the tensile properties of Al–6.5Si–3.5Cu alloy, followed by aging time and solution time. With the increase of solution time, aging temperature and aging time, the strength of the alloy increases, but the elongation decreases. When the solution time is 5 h, the aging temperature is 160 °C and the aging time is 3 h, Al–6.5Si–3.5Cu alloy has suitable tensile properties, the yield strength ≥ 240 MPa, the tensile strength ≥ 320 MPa, and the elongation ≥ 2.5%, which can meet the product design requirements well.