Magnesium and its alloys have become a great sparking topic of research due to their excellent biocompatible and biodegradable behavior. Magnesium and several biocompatible alloying elements were developed long back. The trends are to develop a surface composite of as-cast Mg alloys to control the degradation behavior. In this work, the surface composites of AZ31–TiO2 were developed by friction stir processing (FSP). The influence of spindle speed or tool rotation speed and number of processing passes on mechanical and microstructural performance were analyzed. The tool rotation speeds 720, 1050, 1550 and 2260[Formula: see text]RPM with pass 1, pass 2 and pass 3 were considered. The FSP workpiece was analyzed by microstructure and universal testing machine and the significant improvement in grain refinement and hardness was observed.