A New Constitutive Model for Hot Deformation Behavior of SiCp /2024Al Composites under High Strain Rate

Through the dynamic compression tests of the split Hopkinson pressure bar(SHPB), the thermal deformation behavior of the aluminum-based silicon carbide particle reinforced composite(SiCp/2024Al) with a volume fraction of 45% in a large strain rate and deformation temperature range was studied. The influence of thermal deformation parameters(deformation temperature and strain rate) on flow stress is analyzed. It is found that the deformation temperature and strain rate have significant effects on the flow stress, compressive strength, elastic modulus, and strain rate sensitivity of the composites. The compressive strength and elastic modulus decrease with the increase of deformation temperature, while the compressive strength, elastic modulus and strain rate sensitivity show an inflection point with the increase of strain rate. According to the experimental results, combined with thermodynamics and statistical damage mechanics theory, a continuous damage constitutive model describing the dynamic thermal deformation behavior of SiCp/2024Al composites was established. The predicted flow stress is in good agreement with the experimental ones, indicating that the model established may accurately describe the dynamic thermal deformation behavior of SiCp / 2024Al composites. © 2021, China Mechanical Engineering Magazine Office. All right reserved.