【摘要】 研究了Ti3Al基合金(Ti-24Al-14Nb-3V-0.5Mo-0.3Si,原子分数,％)在500,600,700℃下应力水平对其选择性氧化行为的影响.合金氧化主要形成TiO2和Al2O3的混合膜. XPS与SEM分析表明,在500℃下,拉应力降低氧化物组成中TiO2的含量,增大Al2O3的含量.在600℃下结果与上述相反,且随应力增大,效果愈明显.而在700℃下,施加的外应力水平导致氧化膜发生开裂,氧化膜中相组成与无外应力时的相同.用力学化学活度的理论对实验结果进行了分析和讨论.更多还原

【Abstract】 The effect of external tensile stresses on the selective oxidation of a Ti3Al-base alloy (Ti-24Al-14Nb-3V-0.5Mo-0.3Si, atomic fraction, %) has been investigated. The oxide scales formed under the experimental condition are composed of mixture of TiO2 and Al2O3 mainly. XPS and SEM analysis indicates that the applied tensile stress decreases TiO2 content and increases Al2O3 content in the oxide scale formed on the alloy at 500℃. The result obtained at 600℃is opposite to the above one, and the effect is more significant with increasing tensile stress. The oxide scale formed at 700℃ under applied stress happened to crack, the content of TiO2 and Al2O3 in the oxide scale has no difference with that formed under stress free. The experience results are analyzed based on the mechanochemistry activity theory.更多还原