A surface-layer of steel/SiC nanocomposite was fabricated by multiple passes of friction stir processing (FSP) on a low-carbon steel. The characterization methods such as optical microscopy, field emission scanning electron microscopy, microhardness, and wear test were performed to obtain the microstructure and mechanical properties of the produced layers. The results revealed that the dispersion of nano-SiC particles is directly related to the FSP passes and that the superior scattering of the nanosized SiC particles is achieved at higher FSP passes. Nano-composite surface layers demonstrated an average microhardness value of ~424 HV, which is ~3.4 times higher than that of the as-received substrate. Moreover, ultrafine submicron grains were formed by FSP due to the role of SiC particles as obstacles to grain growth. The produced surface-layer nanocomposite exhibited an outstanding enhancement in wear resistance in comparison with the FSPed sample without reinforcing particles.

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