Mechanical Properties and Wear Resistance of CrSiN Coating Fabricated by Magnetron Sputtering on W18Cr4V Steel

Abstract

To increase the service life of tool materials and further meet the demands of modern high-speed machining, a Si-doping CrN coating consisting of Si3N4 amorphous and CrN nanocrystalline was fabricated on top of W18Cr4V high-speed steel. The effect of coating thickness on its structure and properties was investigated by means of X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), scratch test, nano-indenter, and friction–abrasion tester. The thickness of the coating was modulated by the deposition time. The results show that the coating consists of a CrN phase distributed into an amorphous Si3N4 matrix. As the thickness increased, the surface defects decreased, and the residual compressive stress, hardness, and elastic modulus as well as the H/E and H3/E2 factors increased, improving the wear resistance significantly. The adhesion between coating and substrate increased first and then decreased, and it reached the maximum when the coating thickness was 1.9 μm (deposition 60 min). Moreover, the effect of toughness on wear resistance and the wear mechanisms is discussed.