Formed nano-W - WC coatings on the high-speed steel substrate by the electrodischarge explosion

Electric exploding of a tungsten carbide – cobalt material near-by high-speed steel surface forms on it a hardening coating. The essential structure properties of the formed coatings are determined by specifications of contact exploding electrode and the pulse current amplitude and duration. The investigations of coating structures were done by optical and electronic metallography. They have shown that the contact electric exploding caused the transfer of tungsten carbide and cobalt on the surface of high-speed steel. The breakdown of tungsten carbide – cobalt material took place during electrical exploding. The hardening layers of tungsten carbide and pure nanocrystalline tungsten have been formed upon the surface of high-speed steel as a result of electric exploding. Crystalline grains of tungsten have an almost spherical form and their characteristic size less than 400 nm. Micro hardness of the coating layers and high-speed steel structures was measured. (paper)