Micro-pillar compression tests to characterize the mechanical behavior of a nanocrystalline layer induced by SMAT in a 316L stainless steel
Matériaux & Technique
Micro-pillar compression tests were used to study the mechanical behavior of a stainless steel treated by SMAT (Surface Mechanical Attrition Treatment), particularly the induced nanocrystalline surface layer. Micro-pillars were first machined using a Focused Ion Beam (FIB) on the cross-section of the SMATed specimen. They were then deformed with a flat head mounted on a nanoindenter. Stress-strain curves were obtained for various micro-pillars machined at different distances from the SMATed surface. Deformed micro-pillars after compression tests were examined using FEG SEM to analyze deformation mechanisms. According to the obtained stress-strain curves, the mechanical strength of the stainless steel is significantly improved after SMAT, and the deformation mechanisms of the material appear to be different according to the distance from the treated surface.