Optimized AA7075-Al 2 O 3 composites: Leveraging deformation-driven metallurgy for enhanced performance

Abstract

This study investigates the microstructural evolution and mechanical performance of AA7075-Al₂O₃ composite fabricated via the deformation driven metallurgy at varying rotational speeds (500–1400 rpm). Microstructural analysis revealed uniform equiaxed grain structures across specimens, with grain size increasing from 3.8 µm to 7.6 µm as rotational speed rose. Mechanical testing demonstrated a decline in hardness from 281.6 ± 2.9 HV to 134.1 ± 11.7 HV and in tensile strength from 614.2 MPa to 480.4 ± 12.1 Mpa, attributed to grain growth, precipitate coarsening, and particle clustering. Elongation dropped to a minimum of 9.7 ± 1.1%. Wear resistance also decreased, with wear rates reaching 5.8 ± 0.2 µg/m and friction coefficients peaking at 0.46 ± 0.02 at 1400 rpm.