黄 波1 李 轩1,2 谢小青1 谢文玲1 柳忠彬1
摘 要：研究了Y对电弧熔炼Ti-45Al-6Nb合金组织结构和高温氧化性能的影响。结果表明，不同Y含量的Ti-45Al-6Nb合金均主要由γ+α2片层组织、B2析出相和少量Y2O3组成，微量Y对合金的相组成没有明显的影响，但能够显著细化合金的α2+γ片层组织。高温氧化结果表明，Y能够明显改善Ti-45Al-6Nb合金的高温抗氧化性能，且Y含量为0.3%时效果更优：Ti-45Al-6Nb0.3Y合金在1 000 ℃空气中的氧化速率为3.26×10-2 mg2/(cm4 ·h)，分别是Y含量为0.1%和0.9%时合金氧化速率的41.3%和26.1%，较不含Y合金低约1个数量级。
Effects of Yttrium on the Microstructure and High Temperature Oxidation Behavior of Ti-45Al-6Nb Alloys
Huang Bo1, Li Xuan1,2, Xie Xiaoqing1, Xie Wenling1, Liu Zhongbin1
(1.School of Mechanical Engineering, Sichuan University of Science and Engineering; 2.Artificial Intelligence Laboratory of Sichuan Province)
Abstract: Effects of yttrium on the microstructure and high temperature oxidation behavior of arc melted Ti-45Al-6Nb alloys were investigated. The results show that the obtained Ti-45Al-6Nb alloys with different yttrium are mainly composed of γ+α2 lamellar, B2 precipitate and a small amount of Y2O3. Addition of trace yttrium in the alloy can be ingored for influence on the phase composition of the alloys, however, it can significantly refine α2+γ lamellar structure. High temperature oxidation results show that addition of trace yttrium in Ti-45Al-6Nb alloys can significantly improve the oxidation resistance, especially for the alloy with yttrium concentration of 0.3%. The Ti-45Al-6Nb-0.3Y alloy has an oxidation rate constant of 3.26×10-2 mg2/(cm4·h) at 1 000 ℃ in air, which is account for 41.3% and 26.1% of the alloys with yttrium concentrations of 0.1% and 0.9%, respectively, and about 1 order of magnitude lower than that of the alloy without yttrium addition.
Key Words: Ti-45Al-6Nb Alloy, Y Modification, High Temperature Oxidation, Oxide Film, Oxidation Kinetics