Advantages of nanocomposite coatings deposited by high power pulse magnetron sputtering technology

Recent advantages in PVD coatings for cutting tools enable high speed and dry machining with superior cutting parameters in commercial manufacturing sectors. For this reason hard coatings with high oxidation resistance and thermal stability are used for economically justifiable machining. In this regard nc-(Ti,Al)N/a-Si3N4 films were sputtered on tungsten carbide cutting tools and WC/Co samples by using the high power pulse magnetron sputtering (HPPMS) technology. Coating composition, microstructure and applied properties were investigated by using X-ray diffraction, scanning electron microscope and nanoindentation. The hardness value was about 29 GPa for a Si content of 3.3 at.%. The grain size was about 6 nm. As this study focuses on the thickness uniformity of the coatings, SEM pictures of the cross-section have been taken around the cutting edge to determine the deposition rate and the film growth. The coatings morphology has been compared to middle frequency and direct current sputtered nanocomposite (Ti,Al,Si)N films. The results demonstrate the enhanced HPPMS coatings properties, including a denser structure, a smoother surface and a favourable thickness uniformity.