Influence of Nitrogen Flows on Properties of CrAlN Film Prepared by Mid-frequency Unbalanced Magnetron Sputtering
CrAlN films were deposited by mid-frequency unbalanced magnetron sputtering in order to study the deposition rate,composition,structure,mechanical features and corrosion resistance as a function of nitrogen flow compared with CrN film.The results show CrAlN films present higher hardness value,denser structure and better corrosion resistance as compared with CrN film.With the nitrogen flow increasing,the deposition rate of CrAlN films is decreasing and Cr/Al ratio increasing,the relative intensity of the(200) peak increases and hexagonal crystalline AlN disappears.In addition,the roughness of CrAlN film decreases from 39 nm to 10 nm and the corrosion potential increases.When the nitrogen flow comes to 53 mL/min,the hardness of CrAlN film reaches a maximum value and the film shows the best excellent corrosion resistance.
The development of coating materials and processes was carried out with the objective to reduce material degradation in supercritical water. Based on the test results of bulk coating alloys (FeCrAlY and NiCrAl), two coating processes, plasma spray of dense NiCrAlY and pack aluminizing, have been developed to apply coatings to candidate stainless steels and Ni-based alloys. The SCW test results and microstructure characterization of both coating alloys and coated candidate alloys are presented in this short paper.