Effects of squeeze casting on microstructure and mechanical properties of Al–5Cu–1Mn–0.3Ti alloy

In this work, the microstructure and mechanical properties of the Al–5Cu–1Mn–0.3Ti alloy prepared by different casting processes were investigated. The results showed that direct squeeze casting can further refine the grain and θ-Al₂Cu phase, which is favourable to the uniform distribution of the θ-Al₂Cu phase. The fluffy θ-Al₂Cu/α-Al interface was caused by the severe pressure loss during the indirect squeeze casting process. The strength and elongation of direct squeeze casting alloy are 508 MPa and 18.5%, which are 40.3% and 123% higher than those of the alloys of indirect squeeze casting. The in situ tensile experiments revealed that the crack initiation mechanism of the indirect squeeze casting alloy is the debonding of the θ-Al₂Cu phase at the grain boundaries.