Structure and properties of a hard alloy deposited on a copper substrate by means of a pulsed plasma spray technology

A pulsed plasma spray generator based on a new principle is developed for depositing ceramic-metal, ceramic, and metal coatings on solid substrates. Calculations of the plasma-generator parameters are presented. A hard alloy (W-Co) was deposited on a copper substrate to demonstrate the use of the plasma generator. A Rutherford backscattering (RBS) technique, x-ray diffraction microanalysis of phase composition, diffraction transmission electron microscopy (TEM), and hardness and adhesion measurements were used to examine the hard-alloy coating. It is shown that the coating consists of W-Co crystals with hexagonal and cubic lattices and contains ∼25-nm cobalt α-and β-phase crystallites, with W₃Co₃C particles revealed at the crystallite edges.