Synergistic strengthening of aluminum with SiC by grain refinement and dispersion hardening

Abstract

This study investigates the synergistic effect of SiCp on grain refinement and dispersion hardening in Al matrix composites produced by ball milling followed by hot rolling. Al grains are effectively refined by generating significant dislocations and subsequent dynamic recrystallization during milling. The presence of SiCp stimulates the grain refinement process by more effectively reducing the grain size to ∼40 nm. Furthermore, an increase in the milling speed and duration reduces the grain size and improves the dispersion of SiCp, thereby enhancing the yield strength without any significant loss of ductility. Consequently, SiCp/Al composites exhibit a tensile strength of 430.27 MPa with more than 4% of elongation before failure, indicating a strength enhancement of ∼325% compared to the unmilled pure Al counterpart.