Surface Coating of Tungsten Carbide by Electric Exploding of Contact

Abstract

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 parameters of contact exploding electrode at the pulse current amplitude from above 106 A/cm2 and duration less than 10‐4 s. The metallographic investigations of coating structures were done by microscope “Neophot‐24”. 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 nanometers. Micro hardness of the coating layers and high‐speed steel structures was measured.