Wear and friction characteristics of electrodeposited graphite-bronze composite coatings

The wear and friction properties of G-Cu (Sn) composite coatings containing different amounts of graphite particles were examined. The presence of graphite particles improved antifriction properties of composite coatings. The effects of graphite percent in composite coating, tin content of matrix, load, speed and distance on the coefficient of friction and wear resistance of bronze-graphite composite coatings were studied. The results of the present studies revealed that hardness, wear resistance, coefficient of friction are dependent on volume percentage of graphite in composite coating. It was shown that the composite coating containing approximately 5.4 (vol.%) graphite and matrix with 14.8 wt.% Sn has the best tribological properties. While the lowest coefficient of friction is observed for a specific percent of graphite, sintering has a beneficial effect on both the coefficient of friction and wear resistance. Sintering improves wear resistance and affects on the coefficient of friction. Also roughness of the bronze-graphite composite coatings was determined. Composite coatings showed roughness significantly higher than the bronze alloy coatings. The variations of roughness with current density and graphite percent were investigated.