Preparation of Ni–W–Si3N4 composite coatings and evaluation of their scratch resistance properties

Abstract In this study, Ni–W–Si 3 N 4 nanocomposite coatings have been prepared by codeposition of Si 3 N 4 nanoparticles into Ni–W alloy coatings having different W contents. The surface morphology and elemental contents in the alloy composite coatings have been analyzed by scanning electron microscopy coupled with EDS. Structure and phase composition were evaluated by using X-ray diffraction (XRD). Progressive type of scratch test was carried out by the scratch tester using a diamond indenter. Results indicated that Vickers microhardness of the Ni–W–Si 3 N 4 composite coatings is found to be higher in comparison to the corresponding Ni–W coatings. In addition, a small increase in Vickers microhardness was observed in Ni–W coatings with higher content of tungsten. Apart from that, a significant influence had been found on scratch resistance properties with the codeposition of Si 3 N 4 and variation of W contents in Ni–W–Si 3 N 4 nanocomposite coatings. Ni–W–Si 3 N 4 nanocomposite with 12.7 at% W and 2.1 wt% Si 3 N 4 has shown improved scratch resistance among others.