Enhancing microstructural, tribological and corrosion responses of Al–Zn–Mg–Cu alloy via nano-/micro-Al<subscript>2</subscript>O<subscript>3</subscript> particulates.

In this study, authors reinforced micro (0–10 wt%)- and nano (0.8–1.8 wt%)-Al2O3 particles into the AA7075 matrix to enhance wear resistance. Comprehensive microstructural analysis, including optical microscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, confirmed the development of robust intermetallic compounds and uniform distribution of reinforcements. Using XRD analysis, peak detection of the Al2O3 and MgZn2 was observed. Al, Al2CuMg, and Al8Fe2Si were identified as the primary phases, and monolithic and composite materials both showed minor MgAl2O4 formation. Ball-on-flat tests (5 and 10 N loads) assessed wear and friction behaviors. Potentiodynamic polarization tests were employed to examine the corrosion behavior of both the monolithic alloy and the manufactured composites. The composite with 1.8 wt% nano-Al2O3 at a 5 N load demonstrated a 53% lower wear rate and 16% reduced friction. Predominant wear mechanisms included abrasive, oxidative, adhesive, and delamination. Corrosion test findings indicated that the composite containing (0.8 wt% nano-alumina and 5 wt% micro-alumina) exhibited superior corrosion resistance compared to the monolithic alloy and other composites. [ABSTRACT FROM AUTHOR]