Influence of BN and B 4 C particulates on wear and corrosion resistance of electroplated nickel matrix composite coatings

Abstract

Electrodeposition of nickel–boron nitride–boron carbide (Ni–BN–B₄C) composites was carried out from a Watt's solution containing 50 and 10 g L ¹ of dispersed boron nitride and boron carbide particles respectively. The corrosion behaviour for both Ni and Ni–BN–B₄C deposits was evaluated by polarisation curves in a 3·5% NaCl solution at room temperature. Wear resistance of the composites was also studied using pin on disc technique. Scanning electron microscopy was extensively used to understand the effect of different electroplating conditions on the concentration and distribution of particles. The results showed that BN and B₄C particle concentration in the Ni–BN–B₄C composite film was sensitively dependent on the electroplating current density and bath temperature. Meanwhile, the Ni–BN–B₄C composite films were much more resistant to corrosion and wear than pure Ni coatings.