Microstructure and Selected Mechanical Properties of Hot-Rolled AA2024/SiC Composite Manufactured by Powder Metallurgy

This study investigates the microstructure and mechanical properties of an AA2024/SiC composite produced using powder metallurgy, followed by hot extrusion and multi-pass hot rolling.The composite, containing 5 wt% SiC, was fabricated by hot pressing at 450C, then extruded and rolled with reductions of up to 66.2%.Microstructural analysis revealed uniform distribution of the SiC particles, grain refinement due to dynamic recrystallization (DRX), and enhanced particle dispersion with increasing rolling reduction.The hardness measurements showed significant improvement, with values increasing from 91 HV1 in the extruded state to 112 HV1 after the final rolling pass, and further grew to 151 HV1 after heat treatment.The tensile tests confirmed a strengthening effect, with the yield stress and ultimate tensile strength rising with rolling reduction from 205 MPa and 304 MPa (after initial rolling) to 236 MPa and 352 MPa (after the final rolling), respectively.Solution treatment and aging of the rolled composite resulted in a sharp increase in yield stress and ultimate tensile strength, reaching 293 MPa and 431 MPa after the first pass, increasing to 375 MPa and 484 MPa after the final pass.The study concludes that hot rolling significantly enhances the mechanical performance of AA2024/SiC composites, with grain refinement and particle fragmentation playing key roles in the strengthening mechanisms.