Intermetallic and Electrical Insulator Coatings on High Temperature Alloys, Properties in Liquid-Lithium Environments

Calcium Oxide Coating on Vanadium Alloys in Liquid Lithium

“…Sample thickness were 1.15 mm for V, 1.20 mm for V-10Cr, 1.16 mm for V1Ti, and 0.65 mm for V-5Cr-5Ti. Samples were vacuum-annealed at 1000°C for 2 h, heated at 710°C in Ar-O 2 to reach a proper amount of O charge [2][3][4], and O-homogenized in a vacuum-sealed (quartz) cell for 17 h at 750°C. Several samples were arrayed together, dipped into a Ca-Li pot at 450°C, and then heated to 600°C for 120 h or 700°C for 50 h. The sample tree was raised above the liquid Ca-Li level and shaken to minimize residual Ca-Li around the samples.…”

“…We have chosen to pursue development of in-situ CaO film deposition on the vanadium alloys because CaO is thermodynamically stable in liquid Li, has the highest electrical resistivity desirable for a thin film, forms in-situ, and is greatly beneficial for healing of defects, such as microcracks and open pores [2,3]. Based on its high thermodynamic stability CaO can be formed in-situ to heal most of the defects on insulator coatings.…”