Abstract To improve the wear resistance of cutting tools made of high-speed steel, the Diamond-Like Carbon (DLC) coating appears as a promising alternative. There are several methods to assess wear, however, it is a challenge for manufacturing engineering to work with thin films, due to the uncertainty in the boundary of the substrate and the coating. Based on this concern, this study proposed the evaluation of the tribological behavior of the DLC coating deposited on AISI M35 steel, seeking to predict its behavior in machining conditions based on characterizations, nano-indentation, micro-abrasion and ball-on-disc test. Results showed that the DLC coating produced for this study consists mainly of sp2 hybridizations. The results of the nano-indentation showed that DLC coating may have a better wear resistance when compared to high-speed steel, and the nano-hardness and Young's modulus do not necessarily obey a positive correlation. Compared to high-speed steel, DLC provided reductions of 71% and 69% without micro-abrasive wear and without friction coefficient during sliding, respectively.

Abstract Friction and wear are influenced by the surface conditions of the material, since there is deformation, segregation, generation of oxide films, among others. Roughness is an important characteristic in tribological studies, where the parameters of skewness and kurtosis have greater influence than the conventional parameters Ra and Rq. This study is aimed to investigate the influence of the parameters of skewness Rsk and Rku kurtosis on the surface of the USI AR 360 steel machining by the milling and turning processes in the pin-on-disc sliding wear test. Results showed that surfaces with the same Ra and Rq could be distinguished by the skewness parameter. Different behaviors were observed in the analysis of friction curves, where the skewness effect showed a tendency to reduce the friction coefficient. It was also observed that the feed marks orientation in relation to the sliding direction can influence the tribological behavior of the surfaces.