Fabrication and mechanical properties of tungsten carbide thin films via mist chemical vapor deposition

Tungsten carbide thin films are used as wear-resistant coatings. For such applications, it is industrially advantageous to form high-quality thin films on substrates with large areas or complex shapes under atmospheric pressure. Herein, we investigated the feasibility of forming tungsten carbide thin films using a mist chemical vapor deposition method. WC_1-x thin films with smooth surfaces were obtained at growth temperatures of 650 °C or above, and the elemental composition ratios of C/W and N/W gradually approached 1 and 0, respectively, with increasing growth temperature. The hardness and Young's modulus of the film obtained at 750 °C were 25 GPa and 409 GPa, respectively. The grown WC_1-x films have potential for use as hard coatings.