INFLUENCE OF SURFACE ROUGHNESS ON TRIBOLOGICALPROPERTIES OF HS6-5-2C STEEL WITH AN AlTiN COATING

Abstract

This article defines the effect of surface roughness on a selection of tribological properties of systems withAlTiN coatings. Friction-wear tests were carried out on a tribological tester, which operates as a sphere anddisc assembly in a frictional, sliding motion. The tests were conducted under a load of 10 N over a frictiondistance of 1,000 m. Steel discs made of HS6-5-2C with an AlTiN coating and steel balls made of 100Cr6were used for the test Trials were carried out under lubrication conditions with polyalphaolefin oil PAO 8 andpolyalphaolefin oil containing 1.5% zinc dialkyldithiophosphate (ZDDP). The chemical composition of theAlTiN coating was studied using a scanning electron microscope, and the wear marks on the discs and sphereswere observed. The geometric structure of the samples was analysed before and after the geometric structureof the samples using a interferometer, and after tribological tests. Research has shown that surface roughnessaffects tribological properties. For samples with a higher surface roughness (Sa = 0.61 μm) – unpolished discs– lower linear wear values were obtained than for polished discs (Sa = 0.08 μm). After the introduction of thePAO 8 additive with ZDDP, a reduction in linear wear of 33% and 24% was observed for both polished andunpolished surfaces, respectively.