Effect of Cr on Oxidation Behavior of TiAlNb Alloy

摘要

The effect of Cr on the oxidation behavior of high Nb-TiAl alloy at 1 073 K has been investigated. 2at.% andrn4at.% Cr were added into a newly designed multi-micro-alloying TiAlNb, respectively; Cr-free alloy was referred to as thern0Cr alloy. The effects of Cr addition on the high temperature oxidation behavior of the alloys at 800 ℃ in air have beenrnstudied. As a result, after oxidation in air at 800 ℃ for 200 h, the oxide film of the 0Cr alloy has the least weight gain, butrnits oxidation resistance is the worst in three alloys. With the addition of Cr element, the weight gain rises to a range ofrnballpark, but the oxidation resistance has an apparent improvement, and the oxide film turned compact and protective.rnThe weight gains per unit area through oxidation kinetic curves of the three alloys are 0.526 84 mg/cm~2, 0.632 18 mg/cm~2,rnand 0.672 03 mg/cm~2 respectively from 0Cr to 4Cr. These suggested that the 4Cr alloy displayed best oxidationrnresistance.