Microstructure evolution and dynamic recrystallization nucleation mechanism of medium volume fraction SiCp/Al composite during hot deformation

Abstract

In order to understand the microstructure evolution and the deformation mechanism of medium volume fraction SiCp/Al composite during hot deformation, the hot compression tests of 35 vol%SiCp/2024Al composite were investigated by Gleeble-1500D thermo-mechanical simulators over hot deformation temperatures range of 623–773 K and strain rate of 0.01–10 s−1. The microstructure in different deformation conditions were investigated utilizing OM, SEM and TEM. The results indicated that the flow stress, microstructure evolution, and the deformation mechanism are sensitive to deformation parameters, which can be represented by the Zener-Hollomon parameter (Z) in the hyperbolic sine equation. The softening mechanism, the degree of dynamic recrystallization, the average grain size, the size of precipitates, the dislocation density, and the nucleation mechanism of dynamic recrystallization of the experimental composite is associated with the Z parameter. The specific influence relationships are analyzed, and the interaction laws are obtained.

Keywords

• SiCp/Al composite
• Dynamic recrystallization
• Zener-hollomon parameter
• Hot deformation
• Microstructure evolution
• Nucleation mechanism