IMPROVEMENT OF WEAR-RESISTANCE OF PULSED-LASER DEPOSITED DIAMOND-LIKECARBON-FILMS THROUGH INCORPORATION OF METALS

We have investigated the characteristics of diamond-like carbon (DLC), DLC doped with Cu, and DLC doped with Ti deposited by a sequential pu lsed laser ablation of two targets. The composition of these films was determined by Rutherford backscattering spectrometry and X-ray photoe lectron spectroscopy (XPS). Raman spectroscopy and transmission electr on microscopy studies showed typical features of DLC with a high fract ion of sp(3) bonded carbon in the doped films as well as in the undope d films. Wear resistance measurements made on the samples by means of the 'crater grinding method' showed that DLC + 2.75% Ti has the highes t wear resistance, while that of purr DLC has the lowest amongst the s amples. Careful analysis of the Raman data indicates a significant shi ft to shorter wavelength with the addition of metal, which means that the compressive stress in the DLC films has been reduced. We envisaged that the reduction in the compressive stress promotes the wear resist ance of the coatings. The XPS studies showed evidence for the formatio n of Ti-C bonding in the Ti doped sample. Thus metal-doped DLC coating s are expected to improve the tribological properties and enhance the performance of components coated with metal-doped DLC. (C) 1998 Elsevi er Science S.A. All rights reserved.