TiAl alloy with high Nb content, nominally Ti–45Al–10Nb, was prepared by powder metallurgy, and the oxidation resistance at 850, 900, and 950°C was investigated. The high-temperature oxidation-resistance mechanism and oxidation dynamics were discussed follow-ing the oxide skin morphology and microstructural evolution analysis. The oxide skin structures were similar for 850 and 900°C, with TiO2+Al2O3 mixture covering TiO2 with dispersed Nb2O5. At 950°C, the oxide skin was divided into four sublayers, from the outside to the parent metal: loose TiO2+Al2O3, dense Al2O3, dense TiO2+Nb2O5, and TiO2 matrix with dispersed Nb2O5. The Nb layer suppressed the out-ward diffusion of Ti atoms, hindering the growth of TiO2, and simultaneously promote the formation of a continuous Al2O3 protective layer, providing the alloy with long-term high-temperature oxidation resistance.

Xuchen Jin;Peihao Ye;Hongrui Ji;Zhuanxia Suo;Boxin Wei;Xuewen Li;Wenbin Fang

School of Materials Science and Engineering,Harbin University of Science and Technology,Harbin 150040,China;The State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,China

矿物冶金与材料学报

[1]Xuchen Jin;Peihao Ye;Hongrui Ji;Zhuanxia Suo;Boxin Wei;Xuewen Li;Wenbin Fang-.Oxidation resistance of powder metallurgy Ti–45Al–10Nb alloy at high temperature)[J].矿物冶金与材料学报,2022(12):2232-2240

TiO2+Al2O3,sublayers,TiO2+Nb2O5

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