A study on hot deformation behaviors and microstructures of 10 vol% SiCP/Al–Cu–Mg–Ag composite prepared by spray co-deposition and extrusion

Isothermal compression test is used to investigate the hot deformation behavior of spray co-deposited and extruded 10 vol% SiCP/Al–Cu–Mg–Ag composite. In this study, an accurate strain-compensated model based on Arrhenius constitutive equation is constructed with the corresponding R value of 0.9965 and AARE of 4.05%. The experimental results are in high agreement with the predicted flow stress. Hot deformation activation energy of the SiCP/Al composite (161.685 kJ/mol) is notably higher than that of Al–Cu–Mg–Ag alloy, which is attributed to the dislocations introduced by SiC reinforcement. The microstructure evolution of compressed specimens is characterized using EBSD and TEM. DRX, including CDRX and DDRX, is the main softening mechanism under the hot deformation conditions of high temperature, low strain rate and high strain. The transition of softening mechanism from DRV to DRX is due to the subgrains consuming dislocations and then transforming into DRX grains. Comparing the microstructure under different hot deformation parameters, the recrystallization degree is significantly influenced by temperature, followed by strain rate and strain. In addition, the recrystallization process is impeded by the primary Al2Cu phases, T phases and SiC particles in the composite through hindering the migration of dislocations.