NbZrTiTa高熵合金的高温氧化行为

High-temperature Oxidation Behavior of NbZrTiTa High-entropy Alloy

摘要:

本文通过循环氧化考核法以及XRD、SEM等技术对电弧熔炼制备的NbZrTiTa高熵合金的高温氧化行为进行了细致研究。结果表明：NbZrTiTa高熵合金在1000~1400 ℃温度范围内的氧化速率常数和氧化激活能分别达到1.1×10_^-7~9.8×10_^-7 g_².cm_^-4.s和97 kJ/mol。NbZrTiTa高熵合金的氧化反应类型为内氧化。高温氧化过程中,氧元素沿具有强晶格畸变和大量位错的富TiZr区扩散,并与金属组元发生反应依次生成不饱和氧化物和饱和氧化物。在组元的高活性以及严重的晶格畸变的共同作用下,NbZrTiTa高熵合金具有极高氧化活性,展现出了较强的作为结构释能材料应用的潜力。

Abstract:

The high-temperature oxidation behavior of NbZrTiTa high-entropy alloy (HEA) were characterized by cyclic oxidation test, XRD and SEM. The results reveal that the oxidation kinetics curve of NbZrTiTa HEA in the temperature range of 1000-1400 °C satisfies the parabolic law. The oxidation rate constant and oxidation activation energy achieve 1.1×10_^-7~1×10_^-6 g_².cm_^-4.s和97 kJ/mol, respectively. The oxidation type is internal oxidation. During high-temperature oxidation, oxygen diffuses along the TiZr-rich region with the severe lattice distortion and a large number of dislocations, then reacts with the metal components to form unsaturated oxides and saturated oxides sequentially. Because of the high activity of constituent elements and the severe lattice distortion, NbZrTiTa HEA displays an extremely high oxidation activity then exhibits strong potential as structure energetic material.