Effect of Milling Ball Diameter during Surface Mechanical Attrition Treatment on Microhardness of AISI 316L

Surface mechanical attrition treatment (SMAT) is one of the recently developed techniques to obtain refined grains on metal surface. In this paper, the effect of milling ball diameter during the SMAT on microhardness of AISI 316L is discussed. All samples were treated for 15 minutes. The result shows enhanced microhardness and thickness of hardened layer at the sample's subsurface as the use of larger diameter milling balls