Wang Junfeng, He Qiaobai, Liu Guanqi, Zhang Qi, Liu Guotan, Huang Zhihao, Zhu Xiaoshuo, Fu Yudong
Department of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China.
Shanghai Key Lab of Advanced High-Temperature Materials, Precision Forming and State Key Lab of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Materials (Basel). 2021 Sep 15;14(18):5319. doi: 10.3390/ma14185319.
In this study, the high-temperature oxidation behavior of a series of AlTiNiCuCo high-entropy alloys (HEAs) was explored. The AlTiNiCuCo (x = 0.5, 0.75, 1.0, 1.25, 1.5) series HEAs were prepared using a vacuum induction melting furnace, in which three kinds of AlTiNiCuCo (x = 0.5, 1.0, 1.5) alloys with different Co contents were oxidized at 800 °C for 100 h, and their oxidation kinetic curves were determined. The microstructure, morphology, structure, and phase composition of the oxide film surface and cross-sectional layers of AlTiNiCuCo series HEAs were analyzed using scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), and X-ray diffraction (XRD). The influence of Co content on the high-temperature oxidation resistance of the HEAs was discussed, and the oxidation mechanism was summarized. The results indicate that, at 800 °C, the AlTiNiCuCo (x = 0.5, 1.0, 1.5) series HEAs had dense oxide films and certain high-temperature oxidation resistance. With increasing Co content, the high-temperature oxidation resistance of the alloys also increased. With increasing time at high temperature, there was a significant increase in the contents of oxide species and Ti on the oxide film surface. In the process of high-temperature oxidation of AlTiNiCuCo series HEAs, the interfacial reaction, in which metal elements and oxygen in the alloy form ions through direct contact reaction, initially dominated, then the diffusion process gradually became the dominant oxidation factor as ions diffused and were transported in the oxide film.
在本研究中，探索了一系列AlTiNiCuCo高熵合金（HEAs）的高温氧化行为。采用真空感应熔炼炉制备了AlTiNiCuCo（x = 0.5、0.75、1.0、1.25、1.5）系列高熵合金，其中三种不同Co含量的AlTiNiCuCo（x = 0.5、1.0、1.5）合金在800℃下氧化100 h，并测定了它们的氧化动力学曲线。利用扫描电子显微镜（SEM）、能谱仪（EDS）和X射线衍射仪（XRD）分析了AlTiNiCuCo系列高熵合金氧化膜表面和横截面层的微观结构、形貌、结构和相组成。讨论了Co含量对高熵合金高温抗氧化性能的影响，并总结了氧化机理。结果表明，在800℃时，AlTiNiCuCo（x = 0.5、1.0、1.5）系列高熵合金具有致密的氧化膜和一定的高温抗氧化性能。随着Co含量的增加，合金的高温抗氧化性能也增强。随着高温时间的增加，氧化膜表面的氧化物种类和Ti含量显著增加。在AlTiNiCuCo系列高熵合金的高温氧化过程中，合金中的金属元素与氧通过直接接触反应形成离子的界面反应最初起主导作用，随后随着离子在氧化膜中的扩散和传输，扩散过程逐渐成为主要的氧化因素。
