Microstructure and mechanical properties of a novel Al-Cu-Si-Ce alloy with high strength for additive manufacturing

The mechanical properties and microstructure of a novel Al-Cu-Si-Ce-based alloy produced by selective laser melting (SLM) were studied. The influence of the printing modes on the porosity was investigated. The minimum porosity (0.2 ± 0.05%) was obtained at an overhatch of 130 µm, velocity of 300 mm/s and power of 200 W. The microstructure of the alloy after SLM contains fine particles of solidification origin (Si), Al2Cu and Al8Cu4Ce phases. The solution treatment, quenching and aging heat treatment provide a high ultimate tensile strength of 490 MPa, elongation up to 4% and yield strength at 250°C of 185 MPa. Good combinations of properties make the investigated alloy a prospective material for aircraft applications.