Effect of different volume ratios of SiC and TiO2 reinforcement particles on mono and hybrid surface composites of AA7075-T651 through friction stir processing

In the present work, the different volume ratios of silicon carbide and titanium dioxide particles were incorporated with AA7075-T651 to improve the surface properties using multipass friction stir processing. The metallurgical study of the friction stir processed samples was examined through optical microscopy and field emission scanning electron microscopy with energy-dispersive X-ray analysis. In addition, the microhardness, wear, and corrosion properties were measured and analyzed. The results revealed that the increased amount of SiC particles caused uniform particle dispersion and was devoid of cluster-rich regions within the matrix. The increased volume of SiC particles exhibited a smaller grain size due to higher grain refinement. The sample with 100% SiC showed superior mechanical, tribological, and corrosion properties. The microhardness of sample with 100% SiC was increased by 13.60% compared to base metal, it was also better compared to other composite samples. Similarly, the coefficient of friction, wear rate, and corrosion resistance properties were reduced by 43.24%, 14.98%, and 75%, respectively.