The influence of friction stir processing (FSP) on wear resistance is studied on a thermally sprayed coating in terms of microstructure and mechanical properties. A high-chromium steel coating sprayed on AISI 52100 steel has been processed, and it is shown that FSP can improve the sprayed layer wear resistance compared to the as-sprayed and quenched and tempered condition. It is suggested that improved toughness is the main contribution to wear performance rather than hardness. It is observed that FSP provides increased hardness and toughness simultaneously, while tempering of the quenched AISI 52100 steel increases toughness while hardness decreases. (C) 2014 Elsevier B.V. All rights reserved.