Study On The Tribological Properties Of Selflubricating Coatings Depositied On Ti（C,N） Cermet By Electro-spark Deposition

In order to reduce the friction and wear phenomenon of Ti（C,N）ceramet materials in daily use and increase the service life of their workpiece,this paper chooses to prepare a self-lubricating coating with anti-wear and lubrication function on its surface by using ESD technology,study the morphology and element distribution of the coating surface and section,and optimize its preparation process parameters,to study the tribological properties of the coating in the process of friction and wear,experiments were carried out to analyze the wear mechanism of the self-lubricating coating.The typical morphology of the prepared Cu-MoS₂ self-lubricating coating was analyzed by ESD.The coating surface was flat,but there were still a small number of microcracks and pores,which was caused by the characteristics of rapid cooling and heating in the process of ESD.The EDS analysis of the coating section found that there was element transition from the coating to the substrate,and there was good melting and diffusion effect between the coating and the substrate.According to the single factor experimental method,the ESD experiment is designed to study the variation law of thickness and roughness of self-lubricating coating prepared under different parameters.The self-lubricating coating with the best surface quality was obtained when the pulse voltage was 65V,the p ulse width was 30μs,the discharge frequency was 100Hz,the deposition time was 7min and the electrode speed was 250r/min.The friction and wear properties of lubricating coatings were analyzed with different preparation parameters.The self-lubricating coating with the best friction and wear performance was obtained when the pulse voltage was 50V,the pulse width was 30μs,the discharge frequency was 80Hz,the deposition time was 5min and the electrode speed was250r/min.In this paper,the distribution of the stress and temperature fields during the continuous ESD process was studied using ABAQUS software to obtain the residual stresses in the workpiece during the cooling stage and to investigate the peak residual stresses in the coating with different parameters.The simulation results show that with the movement of the heat source,the node temperature first rises sharply and then falls rapidly.The maximum stresses during deposition occur inside the coating and are mainly tensile stresses along the deposition direction,with the deposition voltage being the main factor affecting the peak residual stresses.The simulation results are in good agreement with the actual deposition experimental results.In this paper,the tribological properties of Cu-MoS₂ self-lubricating coating are studied.The research shows that the friction coefficient and wear amount of self-lubricating coating are affected by load,friction frequency and molybdenum disulfide content in the coating.By observing the wear morphology of the coating surface,the wear mechanism of Cu-MoS₂self-lubricating coating is summarized.Firstly,the micro protrusion on the coating surface is ground flat,and then the solid lubricant powder inside the coating is ground out,forming a self-lubricating thin film with anti-wear and lubrication ability on the contact surface.