THE INFLUENCE OF VARIOUS PROCESS GASES ON THE MAGNETRON SPUTTERING OF ZRB12

Decorative coatings of zirconium boride were deposited on steel and molybdenum substrates employing d.c. magnetron sputter deposition using ZrB12 targets and neon, argon and krypton as process gases. The characterization of the coatings occurred by means of scanning electron microscopy, electron probe microanalysis, X-ray diffraction, Vickers microhardness measurements and quantitative colour analysis. The effect of the ion bombardment caused by the applied bias voltage using various process gases on the film formation was investigated. Measurements of the deposition rates yielded the highest values for neon and argon. In the case of neon and krypton the stoichiometry of the extremely fine-grained films containing the ZrB2 and a distorted boron phase could be varied by using different bias voltages in a wide range, whereas the bombardment with argon ions seemed to have less effect on the stoichiometry. The maximum Vickers microhardness of the highly reflecting silver-grey films was found to be approximately 2200 HV 0.01.