Surface roughness and wettability of AISI 316L induced by surface mechanical attrition treatment with different milling ball diameter

Surface roughness and wettability determines the rate and quality of protein adsorption and cells adhesion on biomaterial. For this case, a rough- and hydrophilic-surface are preferable rather than a smooth- and hydrophobic-one. This paper discusses the effect of milling ball diameter used in surface mechanical attrition treatment (SMAT) on the roughness and wettability of AISI 316L. All samples were treated for 15 minutes with 250 balls whose diameter of 1/8¿, 3/16¿, and 1/4". The result shows enhanced surface roughness and reduced droplet contact angle of AISI 316L surface after SMAT. The ball's radius of curvature influences the pit geometry and the roughness of sample's surface. In addition, the performance of SMAT is still lacking to produce a hydrophilic surface.