Study Of W/Wc Films Produced By Plasma Assisted Vacuum Arc Discharge

W/WC films were grown by the PAPVD repetitive pulsed vacuum arc technique on 304 stainless steel substrates. To produce the coatings, a target of W with purity of 99.9999% was used. The system is composed by a reaction chamber with two opposite electrodes placed inside it. The target is located on the cathode and the samples on the anode. A pulsed power supply is used to generate the discharge. For the production of the W layer, the chamber was filled with Ar gas at a pressure of 3 mbar, and the voltage of the discharge was 270 V with 3 pulses. WC films were grown in an atmosphere of methane at 3 mbar and a voltage discharge of 275 V with 4 pulses. The active and passive times of the discharge were 1 s and 0.5 s, respectively.XRD technique was employed to study the coatings, to study the present phases and the crystallographic orientation of the films, the XRD analyses were carried out varying the temperature of the system-coating-substrate between room temperature and 600 degrees C, when the WC coatings are degradated, leaving just the tugsten. XPS analyses present the apparition of WC, WO and WO2 compounds. AFM analyses allowed to measure the morphological properties and the thickness around 3 mu m. (c) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim..