Mechanical and tribological properties of W/WC coating with C2H2 ionization-assisted deposition

In this paper, a wolfram with wolfram carbide (W/WC) coating, which deposited on a 304 stainless steel and Si wafers, is prepared through co-sputtering by unbalanced magnetron sputtering technology with added C 2 H 2 ionization-assisted deposition. The microstructure and the mechanical properties of the W/WC coating are characterized by the equipment of scanning electron microscopy, X-ray diffraction, Raman, nanoindenter, scratcher, and Rockwell. Besides, a UMT-3 ball-disk reciprocating friction machine is used to study the tribological properties in the environments of atmosphere, deionized water, and seawater. The experimental results show that the C 2 H 2 ionization gains the deposition rate and the carbon content of the W/WC coating, but significantly reduces the density and the relative wolfram content. Moreover, the sp 3 content is increased and the sp 2 content and the graphitization degree of coating are decreased. Compared to the W/WC coating without the C 2 H 2 ionization, the hardness and the elastic modulus of the prepared coating are increased from 12.02 GPa and 179.91 GPa to 19.37 GPa and 269.61 GPa, respectively. In addition, the adhesive strength is reduced from 19.31 N to 9.41 N. For the tribological properties, the friction coefficient and the wear rate of the prepared coating are increased. The prepared W/WC coating is mainly abrasive wear in dry friction and in water.