The surface improvement of Nb to improve the high temperature oxidation resistance wascarried 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 equimolarNaCI-KCI melt containing 1-5 mol%AIF3 at 1023 K. 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-AI alloy phase. The alloy phase consisted of NbAI,. Niobium covered by the Nb aluminide was more resistant than bare niobium to hightemperature oxidation at 1273 K for 10.8 ks in air.
展开▼
