Effect of sputtered TiAlCr coatings on oxidation resistance and hot corrosion resistance of Ti-24Al-14Nb-3V

The effect of sputtered Ti-50Al-10Cr and Ti-50Al-20Cr coatings on both isothermal and cyclic oxidation resistance at 800-900°C and hot corrosion resistance at 850°C of Ti-24Al-14Nb-3V was investigated. Results indicated that Ti-24Al-14Nb-3V alloys exhibited poor oxidation resistance due to the formation of Al 2O 3+TiO 2+AlNbO 4 mixed scales in air at 800-900°C and poor hot corrosion resistance due to the spallation of scales formed in Na 2SO 4+K 2SO 4 melts at 800°C. Both Ti-50Al-10Cr and Ti-50Al-20Cr coatings remarkably improved the oxidation resistance and the hot corrosion resistance of Ti-24Al-14Nb-3V alloy.