Characteristics of electroplated nickel layer on tungsten carbide

Abstract

Diamond coating on tungsten carbide (WC-Co) cuttin g tools with cobalt binder experiences delaminating failure due to the deleter ious effect of cobalt. One of the methods used to reduce this effect is by coating an interlayer onto the substrate surface prior to diamond deposition. Different materials have been used as an interlayer which is normally deposited to the substrate surface using CVD and PVD techniques. Among differe nt materials used as interlayer on WC-Co, nickel is considered as an attractive candidate due its good chemical and physical properties. In this study the potential of the electroplating technique for deposition of nickel interlayer on WC-Co will be investigated. Nickel deposition on WC-6%Co subst rate was carried out by electroplating in a standard watt’s solution at constant plating parame ters (Current: 0.1 Amp, electric potential: 1.0 V and pH: 3.5). The gap between anode and cathode was varied (5mm, 10mm and 15mm). The nickel coating formed on the hard metal surface was charac terized in terms of the coating thickness, layer uniformity and coating hardness by using SEM and th e micro hardness tester. Based on the results, desirable nickel coating properties were obtained w hen the separation distance between anode and cathode was 15mm.