The formation of stable hydrogen impermeable TiN-based coatings on zirconium alloy Zr1%Nb

Abstract

TiN coatings were deposited by DC reactive magnetron sputtering (dcMS) method on Zr1%Nb substrates with different film thickness. The influence of crystalline structure and thickness of the coatings on hydrogen permeation was investigated. The results revealed that the increase in thickness of the film reduced hydrogen permeability. 1.54 [mu]m TiN deposited in N[2]/Ar gas mixture with a ratio of 3/1 reduces hydrogen permeation in more than two orders of magnitude at 350 °С. Adhesion strength decreased with increasing film thickness (0.55 to 2.04 [mu]m) from 7.92 to 6.65 N, respectively. The Ti underlayer applied by arc ion plating (AIP) leads to the formation of stable Ti/TiN coatings on Zr1%Nb under thermocycling conditions up to 800 °С. Meanwhile, hydrogen permeation rate of Ti/TiN deposited by combination of AIP and dcMS remains at the same level with TiN deposited by dcMS.