Analysis liquid lithium corrosion resistance of Er2O3 coating revealed by LIBS technique

Er2O3 could be used to prevent the liquid alkalis corrosion as one candidate material for corrosion resistance coating in self-cooled blanket system of tokamak device. In our work, Er2O3 coatings were deposited on type 316 stainless steel substrates by direct current magnetic sputtering and corroded by liquid lithium for corrosion resistance study. Among the two types implemented deposition methods, one Erbium metal layer was deposited and oxidized successively, and the other directly by reactive sputtering with Er2O3 deposition. Laser-induced breakdown spectroscopy (LIBS) technique was demonstrated to play vital role in revealing the longitudinal element distributions especially for that of lithium in the corroded layer of the specimens with the testing results of XRD and SEM/EDX for phase structure and morphology of the vertical sections. Depth profiles of the elements such as Er, O, Li, Fe, Cr, and Ni as a function of the laser pulse number were obtained based on the internal standard normalization in LIBS measurement in order to reduce the disturbance of matrix effect. The LIBS results are consistent with the EDX line-scanning for the longitudinal cross-section of the target specimen indicates well that the penetration depth of liquid lithium can implicate the corrosion resistance of the oxide layer.