28 research outputs found
Transcriptional profiles in bursal B-lymphoid DT40 cells infected with very virulent infectious bursal disease virus
Local Willingness-to-Pay Estimates for the Remediation of the Sydney Tar Ponds in Nova Scotia
Comparison of Cheeses Made from Milk Having Normal and High Oleic Fatty Acid Compositions
Deposition and Characterization of Tungsten Carbide Thin Films by DC Magnetron Sputtering for Wear-Resistant Applications
In this study, WC (tungsten carbide) thin films were deposited on high-speed steel (AISI M2) and Si (100) substrates by direct current magnetron sputtering of a tungsten carbide target having 7% cobalt as binding material. The properties of the coatings have been modified by the change in the bias voltages from grounded to 200 V. All the coatings were deposited at 250A degrees C constant temperature. The microstructure and the thickness of the films were determined from cross-sectional field-emission gun scanning electron microscope micrographs. The chemical composition of the film was determined by electron probe micro analyzer. The x-ray diffractometer has been used for the phase analyses. Nanoindentation and wear tests were used to determine the mechanical and tribological properties of the films, respectively. It is found that the increase in the bias voltages increased drastically the hardness and elastic modulus, decreased the friction coefficient values and increased the wear resistance of tungsten carbide thin films by a phase transformation from metallic W (tungsten) to a nonstoichiometric WC1-x (tungsten carbide) phase