Reciprocating Wear Behavior of Noncoated and Polymer/Composite Coated AISI 316L Steel: Role of Surface Mechanical Attrition Treatment

Abstract

The current work investigates the reciprocating wear behavior of surface mechanical attrition–treated (SMAT) AISI 316L stainless steel with and without polymer and composite coatings. The high-performance aromatic thermoset polymer (ATSP) and its composite with MoS2 are deposited on non-SMATed and SMATed steel using the spin coating technique. Further, a reciprocating wear test is performed on non-SMATed, SMATed, and coated surfaces against an alumina ball using different loads and reciprocation cycles. Enhanced surface hardness (∼89%), presence of an α′ (body-centered cubic [bcc] Fe) phase, and lower oxidation during reciprocation cause a decrease in wear loss and coefficient of friction (COF) of the SMATed surface by ∼37, and ∼20%, respectively, under 15 N load and most extended reciprocation cycle. The wear loss and COF of the steel are further reduced by depositing ATSP polymer and ATSP-MoS2 composite coatings. The adhesion and durability of coatings are enhanced by the SMAT process. This enhanced durability lowers the wear loss and COF of ATSP and ATSP-MoS2 composite coatings when deposited on the SMATed substrate. Polymer coating reduces the COF of non-SMATed and SMATed steel by ∼68 and ∼85%, respectively. Depending on the concentration of MoS2 in the composite coating, the COF ranges from 0.04 to 0.32 and from 0.02 to 0.07 for non-SMATed and SMATed specimens, respectively. The best performance of a composite coating was observed at ∼10 wt% MoS2. The COF of composite coated steel is ∼96% lower than that of the noncoated and nontreated steel surface. The SMAT processing of substrate and ATSP-MoS2 composite coating considerably enhances the tribological performance of AISI 316L steel. © 2021 Society of Tribologists and Lubrication Engineers.