Structure and properties of WC-Co coatings deposited to Cu substrate using high-velocity pulsed plasma jet with subsequent W ion implantation

It is known, that deposition of protecting coatings on copper crystallizes is seems to be deposition of coatings of a hard alloy WC+15%Co using a high-velocity jet applied in a plasma-detonation technology. To deposit coatings we applied a modified plasmatron 'Impulse-3', in which the jet velocity reached 6 km/s and its temperature was 104 K. The coating structure was comprised of WC (with fcc close-packed lattice), α-β-Co crystallites in WC with a cubic lattice. An average dimension of WC crystallites was 0.15 μm, that of cobalt was 25 nm. We observed particles of W3Co3C phases of 15 nm dimension along the crystallite boundaries. Implantation of W ions was realized using a vacuum-arc implanter 'Diana-3', which energy was 60 and 40 keV, dose reached 2·1017 and 1017 cm-2 respectively for those energies, pulse duration of the ion beam was τp = 200 μs. As a result of implantation the coating roughness decreased, the concentration of W ions at about 50 nm depth from the surface reached about 12 at.%, though in the initial state it amounted only 1 to 2 at.% till the depth of l μm. The coating hardness also increased by 20 %, and the number of pores, being visible in the coating surface, decreased