Reciprocating two-body abrasive wear behavior of DC magnetron sputtered Mo-based coatings on hard-chrome plated AISI 316 stainless steel

The aim of this work was to study the influence of a hard chrome (HC) intermediate layer on the reciprocating abrasive wear behaviour of Mo-based coatings deposited by DC magnetron sputtering on AISI 316 stainless steel. The two-body abrasive wear characteristics of sputtered MoN, MoC and MoCN coatings on AISI 316 stainless steel with an electroplated HC layer were systematically evaluated using test a reciprocating pin-on-flat whose geometry is similar to that of ASTM G133-05 standard, but in this case, the pin was covered with SiC abrasive paper. Data showed that MoN coating had a lower wear rate than either MoC or MoCN coatings. The presence of plated HC on the stainless steel substrate considerably improved the wear resistance of all Mo-based coatings, presumably because of enhanced composite hardness and improved surface quality. One-way analysis of variance and multiple comparisons confirmed that MoN-HC and MoC-HC exhibited statistically insignificant differences in the wear rate, which were considerably lower than those of the other coating combinations. In addition, micro structural analyses suggested that the wear mechanisms for Mo-based coating in the absence of HC involved mainly plowing, cutting and oxidative abrasive wear processes while the wear processes of Mo-coatings on HC were mostly governed by cutting, fragmentation and fatigue wear processes. (C) 2017 Elsevier B.V. All rights reserved.