Control of the preferential orientation Cr coatings deposited on zircaloy substrates and study of their oxidation behavior.

Cr coatings deposited on zircaloy substrates generally exhibit (110) and (200) preferred orientations, which in turn affects the microstructure and oxidation performance of coatings. In this study, the preferential orientation of Cr coatings has been regulated in order to enhance the oxidation resistance of Cr coatings. For the pristine coatings, the deposition rate and surface morphologies depend strongly on the bias voltage and Ar pressure. While the evolutions of the texture coefficients are affected significantly by temperature, bias voltage and Ar pressure, especially for the (110) texture. The oxidation resistance of coatings with different texture has been investigated according to the energy-dispersive X-ray spectrometry. After oxidized in steam at 800 ℃ for 1 h, a transition layer and dispersed particles with higher oxygen content have been discovered. In addition, coatings deposited at pressure higher than 1.0 Pa exhibit through-film cracks and the zirconium substrates have been partially oxidized. [ABSTRACT FROM AUTHOR]