High-temperature oxidation behaviors of an equiatomic CrMnFeCoNi high entropy alloy
High-temperature oxidation behaviors of an equiatomic CrMnFeCoNi high entropy alloy
复制标题
DOI：
10.1016/j.mtcomm.2022.104185
复制
发表时间：
2022-08-08
影响因子：
3.8
通讯作者：
Lei, Qian
中科院分区：
文献类型：
--
作者：
Jiang, Dong;Li, Zhou;Lei, Qian
由于文献中关于高熵合金氧化机理的信息有限，我们研究了等原子Cr20 Mn 20 Fe 20 Co20 Ni 20高熵合金（CrMnFeCoNi HEA）的高温氧化行为以证明氧化机理。利用扫描电子显微镜（SEM）、X射线能谱仪（EDS）和X射线衍射仪（XRD）分析了氧化膜的表面形貌、氧化物生长过程和元素分布。研究结果表明，该合金的氧化过程经历了三个阶段，即：（1）低温下O2-离子与金属离子的表面反应ii）在中等温度下由于O-2原子的化学吸附而使样品表面增厚（950-1050 ℃），和iii）由于高温（1050-1150 ℃）下氧化物剥落而使样品变薄。三个氧化物层被检测到，从外部延伸到内部的样品的横截面和组成的MnFe 2 O 4 + Mn 3 O 4，（Mn，Cr）（x）O-4，和Cr2 O3，分别。随后，通过热力学和动力学计算确定了合金的高温氧化行为。建立了氧化机理模型。这项研究的结果为HEAs的新应用铺平了道路。
Due to the limited information in the literature on the oxidation mechanism of high-entropy alloys, we have investigated the high temperature oxidation behavior of an equiatomic Cr20Mn20Fe20Co20Ni20 high-entropy alloy (CrMnFeCoNi HEA) to demonstrate the oxidation mechanism. The evolution of the surface morphology and the specific oxide growth processes and elemental distributions were analyzed by scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDS), and X-ray diffractometer (XRD). The findings reveal that the alloy undergoes three oxidation stages, which are i) surface reaction between O2- ions and metal ions at low temperatures (750-850 degrees C), ii) thickening of the sample surface due to chemosorption of O-2 atoms at moderate temperatures (950-1050 degrees C), and iii) thinning of the sample due to oxide spalling at high temperatures (1050-1150 degrees C). Three oxide layers were detected, extending from the outside to the inside of the cross sections of the sample and were composed of MnFe2O4 +Mn3O4, (Mn,Cr)(x)O-4, and Cr2O3, respectively. Subsequently, the high-temperature oxidation behavior of the alloy was determined by thermodynamic and kinetic calculations. As a result, an oxidation mechanism model was established. The results of this study have paved the way for new applications of HEAs.