Electrode Materials for Composite and Multilayer Electrospark-Deposited Coatings from Ni–Cr and WC–Co Alloys and Metals

Abstract

The layer-by-layer electrospark deposition of Cu, In, Pb, Cd, and Sn group metals and Ti, V, and W metals, as well as their carbides and hardmetals of WC type, onto metallic surfaces is studied. This technique improves the quality and wear resistance of the surface layer compared to coatings without a sublayer. The sintered electrode materials containing 10–30 wt.% of the (Ni–Cr–Si–B)–WC6 alloy allow electrospark coatings with thickness up to 100 μm and microhardness 12.3–14.2 GPa to be formed. The wear resistance and service life of these coatings are substantially higher than of those made of standard hardmetal WC6. Among the Ni–Cr–Al alloys, the best effectiveness in worn-part recovery is shown by the alloy from the ternary eutectic region (50.3 wt.% Ni, 40.2 wt.% Cr, 9.5 wt.% Al), which may provide coating thickness up to 1.0 mm. The novel coating technique and proposed electrode materials increase the resistance of cutting tools and life of equipment parts.