Microstructure, mechanical, and tribological properties of Al7075-T6/Ti3AlC2/Al2O3 surface hybrid nanocomposite produced by friction stir processing: A comparison of hybrid ratio

This study investigates the effects of incorporating Ti3AlC2 MAX phase into Al7075-T6 alloy by friction stir processing as well as adding Al2O3 nanoparticles to obtain a surface hybrid nanocomposite. These composites were successfully prepared by friction stir processing with a rotational speed of 1000 rpm and a travel speed of 28 mm/min after 3 passes. Optical, atomic force and scanning electron microscopy as well as microhardness, tensile, and wear tests were utilized to characterize the fabricated surface hybrid nanocomposites. Results showed that the maximum tensile strength and hardness value were achieved for Al-100% Al2O3 composite due to more grain refinement and effective dispersion of nanoparticles. Due to its laminar structure, Ti3AlC2 MAX phase enhanced better tribological characterization, whereas Al2O3 nanoparticles cause better mechanical properties. Scanning electron microscopy tests revealed that the wear mechanism changes from adhesive for Al7075 alloy to adhesive-abrasive for the nanocomposite specimens.