(中国科学院金属腐蚀与防护研究所,沈阳 110015)
摘 要: 研究了Ti-50Al,Ti-45Al-10Cr和Ti-50Al-10Cr(%)合金在900~1100℃下的抗循环氧化性能。 结果表明,TiAl在900~1100℃下形成TiO2和Al2O3的混合氧化物膜,抗循环氧化能力差。 在900 ℃时Ti-45Al-10Cr合金尽管形成TiO2和Al2O3的混合氧化物膜,但是循环氧化100次仍未见氧化膜剥落; 而在1000℃时由于粘附性好的Al2O3膜部分覆盖于表面,其抗氧化性能较TiAl的好。在1100 ℃氧化时, Ti-45Al-10Cr合金能形成连续Al2O3膜, 而表现出好的抗循环氧化性能。Ti-50Al-10Cr合金在900~1100℃由于能形成保护性的Al2O3膜,而表现出好的抗循环氧化能力。 因此, 添加Cr可以促进TiAl表面粘附性好的Al2O3膜的形成从而显著地提高TiAl的抗循环氧化能力。
关键字: TiAl金属间化合物 循环氧化 铬
(Institute of Corrosion and Protection of Metals, Chinese Academy of Sciences, Shenyang 110015, P. R. China)
Abstract:The cyclic oxidation behavior of Ti-50Al, Ti-45Al-10Cr and Ti-50Al-10Cr (%) alloys at 900~1100℃ was investigated. The results showed that Cr improved the cyclic oxidation resistance of TiAl effectively. TiAl exhibited poor cyclic oxidation resistance due to the formation of TiO2+Al2O3 complex scale at 900℃~1100℃. At 900℃, Ti-45Al-10Cr alloy formed TiO2+
Al2O3 complex scales similar to that of TiAl, but no spallation of scale occurrs. At 1000 ℃, Al2O3 scale partially covers the alloy surface, so the alloy had better oxidation resistance than TiAl. At 1100℃, Ti-45Al-10Cr alloy formed a protective Al2O3 scale, and exhibited an excellent cyclic oxidation resistance. Moreover, Ti-50Al-10Cr alloy exhibited an excellent cyclic oxidation resistance at 900~1100℃ due to the formation of a protective Al2O3 scale.
Key words: TiAl intermetallics cyclic oxidation chromium