Wear behavior of electroless Ni-P-B4C composite coatings

In this research, the wear of electroless Ni-P and Ni-P-B4C composite coatings was reviewed. Auto catalytic reduction of Ni in nickel sulfate and sodium hypophosphate bath including suspended B4C particles with different concentration was used to create composite coatings with 12, 18, 25 and 33 vol.% of B4C particles. Coatings 35 mm thick were heat treated at 400 deg C for one hour in an argon atmosphere and the wear resistance and friction coefficient of heat-treated samples were determined by block-on-ring tests. All wear tests were carried out at 24 deg C, 35% moisture, 0.164 m/s sliding speed and about 1000 m sliding distance. Graphs show that an electroless Ni-P-B4C composite coating with 25 vol.% of B4C had the best wear resistance against a CK45 steel counterface. [Substrate: low carbon steel].