Abstract
The surface improvement of Nb to improve the high temperature oxidation resistance was carried out by Al electrodeposition using the molten salt as an electrolyte. Electrolysis of Al was conducted using potentiostatic polarization method at constant potentials in an equimolar NaCl-KCl melt containing 1∼5 mol%AlF3 at 1023K. The mass of electrodeposited Al increased with a decrease in polarization potential. Deposits formed at -1.3∼-1.6V (vs. Ag/Ag+ (0.1)) consisted of hemispherical Al phase and lamellar Nb-Al alloy phase. The alloy phase consisted of NbAl3. Niobium covered by the Nb aluminide was more resistant than bare niobium to high temperature oxidation at 1273K for 10.8ks in air.
