Investigation of wear behavior of carbide based coated rolling roll materials under dry and lubricated conditions

Abstract

In this study, the effect of TiCN and WC-Co coatings on the tribological performance of spheroidal graphite cast iron materials was investigated by wear tests under dry and lubricated conditions. The mechanical and physical effects of the coating processes were analysed by microhardness measurements and visual methods (SEM, EDX, XRD). The tribological effect of WC-Co and TiCN coated specimens were investigated by ball-on-plate wear tests carried out under dry and boron oil emulsion (5% concentration) conditions at 50 N load and 60 rpm sliding speed parameters. The friction coefficient and wear volume results were obtained to investigate the effect of the coating process and boron oil emulsion on friction and wear behaviour. The wear mechanisms were determined with SEM images obtained from the worn surfaces and surfaces analysed elementally with EDX images. Additionally, surface morphology was examined with surface roughness measurements and 2D–3D topography images. According to the microhardness measurement results, it was observed that the spheroidal graphite cast iron with 290 HV hardness reached 1559 HV with TiCN coating and 1440 HV with WC-Co coating. According to the wear test results, it was determined that TiCN and WC-Co coatings decreased the friction coefficient by 32.51% and 12.80%, respectively. When the effect of boron oil usage compared to dry environmental conditions, it was concluded that the friction coefficient and wear volume decreased by a maximum of 54.80% and 53.70%, respectively. Additionally, the roughness values decreased in the experiments where the boron oil emulsion was used. However, although the TiCN coating improved the surface quality, the WC coating negatively affected the surface quality. Surface form images obtained with 2D and 3D topography also support the alteration in roughness values.