The compressive properties of 2024Al matrix composites reinforced with high content SiC particles at various strain rates

The dynamic compressive properties of 2024 aluminum matrix composites reinforced with 40 and 50 vol.% SiC paticles (SiCp/2024Al composites) were investigated at various strain rates ranging from 1250 to 2500 s−1 using split Hopkinson pressure bar (SHPB). The results showed that the flow stress was strain-rate sensitive. The composites displayed different deformation mechanism at various strain rates. The flow stress kept increasing for 40 vol.% SiCp/2024Al and showed increase–decrease tendency for 50 vol.% SiCp/2024Al at high strain rates, and plastic strain of the composite exhibited considerable increase at high strain rates compared with the quasi-static values. The adiabatic heat generated during dynamic compression led to matrix softening/melting, which caused the instantaneous instability of composites with high reinforcement content under dynamic loading. The fracture surfaces were characterized by scanning electron microscopy. It was obvious that the matrix was softened/melted by heat generated during adiabatic compression.