Nanostructured surface layer on metallic materials induced by surface mechanical attrition treatment

In terms of the grain refinement mechanism induced by plastic straining, a novel surface mechanical attrition treatment (SMAT) was developed for synthesizing a nanostructured surface layer on metallic materials in order to upgrade the overall properties and performance. In this paper, the SMAT technique and the microstructure of the SMAT surface layer will be described. The grain refinement mechanism of the surface layer during the SMAT will be analyzed in terms of the microstructure observations in several typical materials. Obvious enhancements in mechanical properties and tribological properties of the nanostructured surface layer in different materials were observed. Further development and prospects will be addressed with respect to the SMAT as well as the performance and technological applications of the engineering materials with the nanostructured surface layer.