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 d epositing ceramic-metal, ceramic, and metal coatings on solid substrates. C alculations of the plasma-generator parameters are presented. A hard alloy (W-Co) was deposited on a copper substrate to demonstrate the use of the pl asma generator. A Rutherford backscattering (RBS) technique, x-ray diffract ion microanalysis of phase composition, diffraction transmission electron m icroscopy (TEM), and hardness and adhesion measurements were used to examin e the hard-alloy coating. It is shown that the coating consists of W-Co cry stals with hexagonal and cubic lattices and contains similar to 25-nm cobal t alpha- and beta -phase crystallites, with W3Co3C particles revealed at th e crystallite edges. (C) 2001 MAIK "Nauka/Interperiodica".