Optimization of cold spray additive manufactured AA2024/Al₂O₃ metal matrix composite with heat treatment

In this study, the effects of annealing and solution aging heat treatment on the microstructure and mechanical properties of cold spray additive manufactured (CSAMed) AA2024/Al₂O₃ composite were investigated. The results showed that both annealing and solution aging enhanced the interfacial bonding between the deposited AA2024 particles in the composite. The tensile properties of CSAMed AA2024/Al₂O₃ composite were significantly improved by 13.8% for ultimate tensile strength and 47.8% for elongation after solution aging. Microstructural examination and fractographic analysis showed that the fracture mechanism between the adjacent AA2024 particles changed from brittle to ductile-dominant mode after heat treatment. However, the interfacial bonding between the AA2024 and Al₂O₃ particles cannot be improved. For the improvement of mechanical properties, the solution aging was slightly better than annealing. In addition, low-temperature annealing greatly reduced the anisotropy of the mechanical properties of CSAMed AA2024/Al₂O₃ composite.