APPLICATION OF NICKEL-PLATING FOR THE SYNTHESIS OF CHEMICAL-VAPOR-DEPOSITION OF DIAMOND ON STEELS

The major problem with wear-resistant diamond coatings in applications is the poor adhesion. The application of a buffer material holds some promise and has shown some successes. In this study, a commercially a vailable process of electroless nickel plating was applied to steel as an intermediate layer for diamond chemical vapour depositions, by rea son of the buffering material being softer than diamond and the stress relaxing, with increasing nickel thickness. Both continuous diamond f ilm on a nickel plate and discrete diamond particles embedded in a nic kel matrix were formed in a microwave plasma-assisted chemical vapour deposition system. The results of tribotesting indicated that the cont inuous diamond film as top coating usually suffers from the microcrack s, while the composite-like coating improves the wear resistance signi ficantly, though at the expense of losing some surface hardness in com parison with that of the pure diamond coating.