Electrode Materials and Composite and Multilayer Spark-Deposited Coatings From Ni–Cr and WC–Co Alloys and Metals

Abstract

The layer-by-layer electrospark coating of metal surfaces by Cu, In, Pb, Cd, and Sn group metals, as well as by Ti, V, W, carbides, and hard alloys of WC type is studied. This method allows improvement in the quality and wear resistance of the surface layer in comparison with surfaces without a sublayer. It is found that the sintered electrode materials with 10–30 wt.% of the ( Ni–Cr–Si–B)–WC6 alloy permit forming electrospark coatings with thickness up to 100 µm and microhardness 12.3–14.2 GPa. The wear resistance and durability of these coatings are substantially higher than those of standard WC hard alloy coatings. Among the Ni–Cr–Al alloys, the best effectiveness in worn-part recovery is shown by an alloy from the three-component eutectic area (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 method and proposed electrode materials allow increase in the resistance of cutting tools and durability of equipment parts.