Preparation Of Self-Lubricating Composite Coating And Research On Friction&Wear Performance

This paper utilizes the method of composite electrodeposition to prepare the self-lubricating composite coating of nickel-molybdenum disulfide.Through orthogonal experiment L9(34), basic plating bath was optimized. This paper did some research on the effect of process parameters to the deposition rate of the composite coating and composite volume, including the cathode current density, pH value and the amount of the particles of molybdenum disulfide added. The dispersion method of solid particles in the plating bath was explored. With appropriate choice of additives, particles were made co-deposited with metal ions so that self-lubricating composite coating of a uniform particle size distribution, good self-lubricity and excellent wear resistance was prepared. The morphology and the organizational structure of the composite coatings were analyzed and research was did on friction and wear characteristics under different conditions. This paper analyzed and calculated the stress and its distribution with friction to explore the friction and wear mechanisms of the composite coating materials.Ring-block friction and wear tests of composite coating material were done at room temperature and dry friction conditions, and come to the laws of friction coefficient and wear rate of composite coatings with the load and speed changes. The results showed that:When the load is the same as the speed increases, the friction coefficient and wear rate decreases; when the speed is the same as the load increase, their coefficient of friction is also reduced, but the wear rate will rise. When the friction between composite coating material and45#steel take place, the friction coefficient is greater than the friction coefficient of friction with carbide, but the wear rate is less than the wear rate of friction with carbide. The wear mechanism is different during the friction process. The wear mechanism of pure nickel coating is mainly based on brittle fracture and grain off the main, while the wear mechanism of Ni-of MoS2composite coating is mainly based on abrasive wear mechanism.This paper uses ANSYS finite element analysis software to establish a the finite element analysis model of ring-block friction and wear of self-lubricating composite coating material. The stress and its distribution of materials in the process of friction and wear is analyzed and calculated. The results showed that:the stress of Ni-of MoS2composite coating in the friction process is much smaller than the bending strength. While the poor wear resistance of pure nickel coating is mainly because its flexural strength and fracture toughness is relatively small, and the stress during the friction process is huge. To the pure nickel coating materials, whether it was rubbed with45#steel or carbide on friction wear tester, the maximum principal stress and shear stress increased with increasing load, and the increase was also larger, while effect of speed on the stress was relatively small. With the addition of solid lubricant, principal stress and shear stress of self-lubricating composite coating material of MoS2are significantly reduced when the friction take place.