High specific strength, superior damping capability, and excellent specific stiffness make magnesium and its alloys a great alternative for usage in the automotive and transportation industries, particularly for electric cars. The AZ91 is a desirable option among magnesium alloys for different applications due to its superior casting qualities.; however, the main obstacles to their widespread usage are their poor surface qualities and lack of corrosion resistance. Thus, the current study aims to enhance surface strength by fabricating AZ91/SiC surface composites. Friction stir processing (FSP) is utilized to refine the microstructures and fabricate the surface composites without introducing any intrinsic flaws. Tool Rotational Speed (TRS), Tool Traverse Speed (TTS), Tool Pin length (PL), and Plunge Depth (PD) were chosen as parameters to investigate their effect on processed materials. Range of 5001500rpm and 20-60 mm/min of TRS and TTS were found to be effective respectively. It was discovered that PL of 3 mm with 3.3 mm PD was successful in producing surface composites with no flaws. The microstructure of the composite band lowers the granule size from 70 μ \mathrmm to 10 μ \mathrmm. Subsequently, the strengthening mechanism was attributed to the enhancement of hardness and achieved 15 higher than that of BM. © 2022 IEEE.