Lubricated sliding of CFRPEEK/AlCrN film tribo-pair and its effect on the mechanical properties and structural integrity of the AlCrN film

Abstract

The tribological behavior of AlCrN film against carbon-reinforced PEEK (CFRPEEK) was investigated using pin-on-disc tribometer in simulated body fluid (SBF) lubrication. The materials were characterized using XRD, AFM, Raman spectroscopy, nanoindentation and nanoscratch tests to understand their structural make-up and mechanical behavior. Post tribotests, the worn coated surface was further analyzed using nanoindentation test, nanoscratch test and Raman spectroscopy to evaluate the effect of the lubricated sliding on the structural integrity and mechanical properties of the AlCrN film. Findings showed that the AlCrN film was composed of dominant cubic CrN structure while CFRPEEK registered intensity peak in XRD attributed to carbon introduction in the PEEK matrix. The p-h plot indicated elastoplastic nature of the AlCrN film inducing high hardness and elastic modulus while CFRPEEK had suffered significant plastic deformation. In simulated tribotest, the AlCrN film witnessed mild abrasion whereas CFRPEEK showcased deformation and fracture induced tearing and fiber pull-out. What is more, the worn AlCrN surface retained its compositional integrity and preserved its indentation hardness, scratch hardness, elastic modulus and H/E attribute as suggestive from the one-way ANOVA test with Tukey's grouping.