Investigation of the adhesion and wear of metal containing amorphous carbon coatings

Physical Vapour Deposited (PVD) hard coatings are being used to provide improvements in mechanical, tribological and decorative properties on a wide variety of substrate materials. This paper deals with a complex PVD hard coating consisting of a series of interlayers with graded interfaces: Ti, TiN, TiCN, TiC, a-C:Ti. The top layer was examined by Raman spectroscopy and found to be a diamond-like carbon coating. The incorporation of titanium causes relaxation of compressive stress allowing the coating to be deposited at thicknesses much larger than normal. The effect of varying the magnetron sputtering deposition parameters is discussed in relation to the variation of the coatings mechanical properties including adhesion, wear resistance and hardness.