The effect of laser cladding coating on the friction and wear resistance of hydraulic pump

As an important turbocharging equipment, hydraulic pumps are prone to internal wear and corrosion problems. In order to improve its friction and wear performance, a ceramic coating strengthening scheme based on laser cladding technology was proposed. The roughness, thickness, width, hardness, and residual stress of the coating under different laser powers and scanning rates were measured, and the effect of process parameters on the coating structure was determined to ensure the optimal basic mechanical properties of the coating. Under the experimental conditions of 10–30 N pressure and 10–20 mm/s lubricated friction velocity, high cycle tribological tests were conducted, and the changes in average friction coefficient, wear amount, and surface wear mechanism were compared and analyzed. To verify the impact of reinforced coatings on corrosive environments, friction and wear tests were conducted in hydraulic oil environment with a pH of 6.4 and particle impurity content of approximately 5 %. Through electron microscopy, the friction morphology was observed and the wear mechanism was analyzed. In order to study the effects of different overloads (including temperature and pressure loads) on friction damage, overload friction damage analysis was conducted under low cycle fatigue loading conditions. The Rtec friction machine was applied, and the test temperature and pressure were set at 400 °C, 500 °C, 750 MPa, and 1000 MPa, respectively. The coating sample speed was set to 500 r/min and the slip rate is set to 5 %. Each sample was worn for 4 cycles under different pressures, with each cycle worn for 1 hour, then the surface roughness morphology and micro wear morphology were obtained. The research results indicate that the friction stability, wear resistance, and hardness of the coating have significantly improved, and it has stronger adaptability to hard or sharp materials, making it very suitable for the working environment of hydraulic pumps.