The oxidation and hot corrosion behavior of Ti2AlNb-based alloy with and without enamel coating at 800℃was investigated. The results indicated that Ti-22Al-25Nb alloy exhibited poor oxidation resistance at 800℃. The...The oxidation and hot corrosion behavior of Ti2AlNb-based alloy with and without enamel coating at 800℃was investigated. The results indicated that Ti-22Al-25Nb alloy exhibited poor oxidation resistance at 800℃. The constitution of oxide scale had the effect on its oxidation rate. Because of the S and Cl accelerating the corrosion process, Ti-22Al-25Nb alloy suffered severe hot corrosion and exhibited very poor hot corrosion resistance. Enamel coating could remarkably improve the high temperature oxidation resistance of Ti-22Al-25Nb alloy because it had good chemical stability and matched thermal expansion coefficient with the substrate. In (Na,K)2SO4+NaCl molten salts at 800℃, chemical reactions between molten salts and enamel coating occurred and complicated products formed on the surface of the enamel coating; Cl- in the molten salts could penetrate through the coating and induced the substrate corrosion, but enamel coating still had good hot corrosion resistance.展开更多
The effect of sputtered Ti-50Al-10Cr and Ti-50A1-20Cr coatings on both isothermal and cyclic oxidation resistance at 800-900℃ and hot corrosion resistance at 850℃ of Ti-24Al-14Nb-3V was investigated. Results indicat...The effect of sputtered Ti-50Al-10Cr and Ti-50A1-20Cr coatings on both isothermal and cyclic oxidation resistance at 800-900℃ and hot corrosion resistance at 850℃ of Ti-24Al-14Nb-3V was investigated. Results indicated that Ti-24Al-14Nb-3V alloys exhibited poor oxidation resistance due to the formation of Al2O3+TiO2+AlNbO4 mixed scales in air at 800-900℃ and poor hot corrosion resistance due to the spoliation of scales formed in Na2SO4+K2SO4 melts at 850℃. Both Ti-50Al-10Cr and Ti-50Al-20Cr coatings remarkably improved the oxidation and hot corrosion resistance of Ti-24Al-14Nb-3V alloy.展开更多
The oxidation and hot corrosion behavior of Co-Ni-Cr-AI-Ta-Y coating produced by magnetron sputtering with and without enamel coating has been investigated in air at 900℃ and in molten 75 wt pct NaCl+25 wt pct Na2SO4...The oxidation and hot corrosion behavior of Co-Ni-Cr-AI-Ta-Y coating produced by magnetron sputtering with and without enamel coating has been investigated in air at 900℃ and in molten 75 wt pct NaCl+25 wt pct Na2SO4 at 850℃. The results show that the enamel coating possesses good hot corrosion resistance in the molten salts, in comparison with the sputtered Co-Ni-Cr-AI-Ta-Y coating. In the hot corrosion test, breakaway corrosion did not occur on the samples with enamel coating and the composition of enamel coating did not significantly change either. The oxidation resistance of the sputtered coating, which offers good adhesion, can be improved by the enamel coating.展开更多
基金Projects supported by the National High Technology Research & Development Program of Chinathe Key Program of the Chinese Academy of Sciences
文摘The oxidation and hot corrosion behavior of Ti2AlNb-based alloy with and without enamel coating at 800℃was investigated. The results indicated that Ti-22Al-25Nb alloy exhibited poor oxidation resistance at 800℃. The constitution of oxide scale had the effect on its oxidation rate. Because of the S and Cl accelerating the corrosion process, Ti-22Al-25Nb alloy suffered severe hot corrosion and exhibited very poor hot corrosion resistance. Enamel coating could remarkably improve the high temperature oxidation resistance of Ti-22Al-25Nb alloy because it had good chemical stability and matched thermal expansion coefficient with the substrate. In (Na,K)2SO4+NaCl molten salts at 800℃, chemical reactions between molten salts and enamel coating occurred and complicated products formed on the surface of the enamel coating; Cl- in the molten salts could penetrate through the coating and induced the substrate corrosion, but enamel coating still had good hot corrosion resistance.
文摘The effect of sputtered Ti-50Al-10Cr and Ti-50A1-20Cr coatings on both isothermal and cyclic oxidation resistance at 800-900℃ and hot corrosion resistance at 850℃ of Ti-24Al-14Nb-3V was investigated. Results indicated that Ti-24Al-14Nb-3V alloys exhibited poor oxidation resistance due to the formation of Al2O3+TiO2+AlNbO4 mixed scales in air at 800-900℃ and poor hot corrosion resistance due to the spoliation of scales formed in Na2SO4+K2SO4 melts at 850℃. Both Ti-50Al-10Cr and Ti-50Al-20Cr coatings remarkably improved the oxidation and hot corrosion resistance of Ti-24Al-14Nb-3V alloy.
基金This work was supported by the National Natural Science Foundation of China(Grant No.59971052).
文摘The oxidation and hot corrosion behavior of Co-Ni-Cr-AI-Ta-Y coating produced by magnetron sputtering with and without enamel coating has been investigated in air at 900℃ and in molten 75 wt pct NaCl+25 wt pct Na2SO4 at 850℃. The results show that the enamel coating possesses good hot corrosion resistance in the molten salts, in comparison with the sputtered Co-Ni-Cr-AI-Ta-Y coating. In the hot corrosion test, breakaway corrosion did not occur on the samples with enamel coating and the composition of enamel coating did not significantly change either. The oxidation resistance of the sputtered coating, which offers good adhesion, can be improved by the enamel coating.