Hot deformation behavior and microstructural evolution of SiCp/Al-4.2Cu-4.1Mg composites

This study investigates the hot deformation behavior and microstructural evolution of 30 vol% SiCp/Al-4.2Cu-4.1Mg composites. Stress-strain curves were obtained through isothermal hot compression tests (deformation temperatures 350–500 °C, strain rates 0.01–10 s −1 ), and an Arrhenius-type constitutive model accounting for strain compensation was established. Calculations yielded a thermal activation energy of 246.16 kJ mol −1 for the material, with high predictive accuracy from the model. A hot processing map based on the Dynamic Material Model (DMM) identified an optimal processing window of 490–500 °C and 0.01–0.03 s −1 . Microstructural analysis revealed that within the stable region, precipitation phase particles dominate microstructural evolution by inducing nucleation and growth of dynamic recrystallization. In the unstable region, SiC particles exhibit cracking or even fracture, accompanied by significant dislocation accumulation. Dislocation activity becomes the primary driving force for microstructural evolution. These findings provide scientific basis and engineering guidance for optimizing the hot processing of this type of composite material.