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.

Keywords:

• SMAT
• friction
• ATSP
• tribology
• MoS₂

Acknowledgement

The authors are grateful to the Department of Metallurgical Engineering and Materials Science, IIT Bombay, for providing access to the EBSD facility.

Conflict of interest

The authors declare that they have no known competing for financial interests or personal relationships that could have appeared to influence the work reported in this article.

Funding

The authors thank the Science and Engineering Research Board (Grant No. EMR/2017/001196) for their financial support.

Table 1. Volume loss of the specimens (discs) and counterball during reciprocating wear.

Additional information

Funding

The authors thank the Science and Engineering Research Board (Grant No. EMR/2017/001196) for their financial support.