OVERVIEW OF RESEARCH ON SURFACE MECHANICAL ATTRITION TREATMENT (SMAT)

Abstract: This paper is an effort to put forth a cumulative presentation of the research being carried out on Surface Mechanical Attrition Treatment (SMAT). SMAT is in some ways similar to Shot-Penning, but differs from it in Ball Size and also the angle of attack. Ball sizes in Shot-penning is in the range of 200μm-1mm, whereas in SMAT it varies from 300μm-10mm[1] so the ball size is greater in SMAT and the angle of attack or impact in Shot-Penning is 90˚, but in SMAT the balls impact the specimen at random angles. This paper will discuss all the research that has been carried out on SMAT, like the effect of it on hardness, corrosion, phase transformation, etc. It was observed that Corrosion resistance depleted after SMAT, and the hardness of the treated surface increased but gradually decreased with increasing depth from the treated surface, the significant observation is the reduction in the grain size from a few μm to nm. The outcome of all the research work has been explained in detail in this paper.

Keywords: Surface Mechanical Attrition Treatment (SMAT), Nancrystalization, Potentiodynamic Polarization, Phase Transformation.