Effect of Si-incorporation on the structure, mechanical, tribological and corrosion properties of WSiN coatings

Abstract

WSiN coatings with silicon content ranging from 0 to 27.7 at.% were deposited by reactive magnetron sputtering technique. The structure, mechanical, tribological properties and corrosion performance were investigated by XPS, XRD, SEM, HRTEM, nano-indentation CSM, ball-on-disc tribo-meter, AFM, Bruker 3D Profiler and corrosion testers. The results indicated that the incorporation of silicon did not affect the cubic structure. WSiN coatings consist of WSiN and amorphous Si3N4 phases. The incorporation of silicon induced the crystallite size refinement and reduced the average roughness. The growth pattern changed from continuous columnar to discontinuous columnar. The hardness first increased and then decreased. The highest hardness of 37.0GPa was maintained as the silicon content was 13.4 at.%. The friction coefficient and wear rate of WSiN coatings first decreased and then increased with increasing silicon content. The best wear resistance was found for the coating which has the highest hardness. The corrosion resistance of the substrate which coated with W2N or WSiN coatings was superior to the bare substrate. The corrosion resistance of the W2N coatings was improved by doping some silicon content.