Li Yongquan, Li Jilin, Qin Chun, et al. Isothermal Oxidation Behavior of DZ125 Alloy[J]. Special Casting & Nonferrous Alloys, 2018,38(4):349-352. DOI: 10.15980/j.tzzz.2018.04.001.
DZ125合金抗高温氧化性能研究
摘要
研究了DZ125合金在1 100℃时的氧化行为
分析了该合金表面氧化膜的生成和失效机制。结果表明
1 100℃氧化30h后DZ125合金表面氧化膜呈分层结构
其中外层为Cr
2
O
3
中间层为NiO及NiCr
2
O
4
内层为Al
2
O
3
。DZ125合金在1 100℃空气中的氧化动力学满足抛物线规律。在氧化过程中
聚集于晶界区域的Hf、Ta等高活性元素会优先发生氧化
为O的向内扩散提供通道
造成合金的选择性内氧化
并且随着氧化时间延长
氧化膜在应力的作用下开裂
最终导致膜层剥落失效。
Abstract
The oxidation behavior of DZ125 alloy at 1 100℃ was investigated
and the formation and failure mechanisms of the oxide film were evaluated.The results show that the oxide film formed on DZ125 alloy has a three-layer structure
mainly composed of a Cr
2
O
3
outer layer
a NiO and NiCr
2
O
4
middle layer and an Al
2
O
3
inner layer.The oxidation kinetics of DZ125 alloy at 1 100℃follows a parabolic law.During the oxidation process
high activity elements of Hf and Ta segregated at the grain boundaries of the alloy can be oxidized preferentially
which provide the inward diffusion path for oxygen and lead to the interior oxidation of the alloy.With the prolongation of oxidation time
the oxide film is cracked and failure under the action of stress.