Y对Ti-45Al-6Nb合金组织结构和高温氧化性能的影响

Effects of Yttrium on the Microstructure and High Temperature Oxidation Behavior of Ti-45Al-6Nb Alloys

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-6Nb-0.3Y合金在1000℃空气中的氧化速率为3.26×10^-2 mg^2/(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 arc melted Ti-45 Al-6 Nb alloys were investigated.The results show that the obtained Ti-45 Al-6 Nb alloys with different yttrium are mainly composed ofγ+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 refineα2+γlamellar structure.High temperature oxidation results show that addition of trace yttrium in Ti-45 Al-6 Nb alloys can significantly improve the oxidation resistance,especially for the alloy with yttrium concentration of 0.3%.The Ti-45 Al-6 Nb-0.3 Y alloy has an oxidation rate constant of 3.26×10^-2 mg^2/(cm4·h)at 1000℃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.