Comparative Wear Analysis of Ion Plasma Coatings Based on Adhesion Properties During Sliding Friction

The present paper aims to analyze the wear of TiAlN and CrAlSiN vacuum ion-plasma coatings applied as thin films to carburized and nitrided steel samples, with thicknesses ranging from 0.8 to 4.0 μm. Both dynamic and continuous indentation techniques were used to determine the mechanical and adhesive properties of the coatings. The wear properties of the coatings were defined through tribological sliding friction tests employing the “pin-plate” scheme. The experimental data also include the results of elemental composition detection of coatings and electron microscopic investigations of their structure, morphology, and wear mechanisms, as defined during tribological testing when examining friction tracks. We have found that the wear of coatings during friction does not exhibit stable correlations with any mechanical characteristic, such as hardness H, elastic modulus E, or their ratios H/2, H3/E2, or the adhesion criterion \(F_{N}^{c}\) , which is the coating's critical shear load as determined by scratch testing. To predict the amount of wear of the ion-plasma nitride coatings, it was suggested to use the G-parameter, the reciprocal value of peeling the coating off the substrate. G is a function of the adhesion parameter \(F_{N}^{c}\) and significantly depends on the physical and mechanical parameters, including the elastic modulus E and the coating resistance to plastic deformation H3/E2. Experimental results revealed an acceptable correlation with the specific volumetric wear of TiAlN and CrAlSiN coatings.