Obtaining Superhard Coatings of Cubic Tungsten Carbide under High-speed Plasma Spraying

摘要

Cubic tungsten carbide WCl-x is one of the most poorly studied phases of the W-C system due to the difficulty of obtaining WC_l-xby most known methods and its instability under heating. This makes it difficult to obtain WC_l-xin bulk form and measure its physical and mechanical properties. In this work, cubic tungsten carbide was synthesized in the form of a coating by the plasma dynamic method. The process was implemented under highspeed spraying of an electric discharge W-C plasma on copper and titanium substrates. As a result, the coating has a sandwich structure Cu-WC_1-x-Cutsubstratc) or (TiC+WC_l-x)-Ti- (WC_l-x+TiC)-Ti(substrate) with a thickness of the WC_l-xlayer up to ~10 μm, Direct measurements of WC_l-xmechanical properties were carried out for the first time. The maximum values of nanohardness and Young's modulus of the WC_l-xlayer are Hv = 31.0±0.8 and E = 310±12 GPa respectively.