The oxidation behavior of the quinary FeCoNiCrSix high-entropy alloys
The oxidation behavior of the quinary FeCoNiCrSix high-entropy alloys
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DOI：
10.1016/j.matchemphys.2017.06.017
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发表时间：
2018-05-01
影响因子：
4.6
通讯作者：
Kai, J. J.
中科院分区：
文献类型：
--
作者：
Kai, W.;Cheng, F. P.;Kai, J. J.
研究了三种五元FeCoNiCrSix高熵合金（x = 0.25，0.5和1.0）在700-900 ℃干燥空气中和900 ℃各种含O-2气氛中的氧化（仅FeCoNiCrSi0.5）。两种低硅含量的合金均为FCC单相结构，而等摩尔含量的合金为BCC + FCC双相结构。所有合金的氧化动力学均遵循抛物线规律，氧化速率常数随温度的升高和Si含量的降低而增大。此外，FeCoNiCrSi0.5合金的氧化速率常数随着氧分压的增加而稳步增加，这表明典型的氧化皮表现出p型电阻率。在所有合金上形成的氧化皮主要由Cr2 O3和少量SiO2（α-石英）组成。HEAs的氧化机制主要是由于阳离子的向外扩散。(C)2017爱思唯尔B. V.保留所有权利。
The oxidation of three quinary FeCoNiCrSix high-entropy alloys (x = 0.25, 0.5 and 1.0) was investigated at 700-900 degrees C in dry air and at 900 degrees C in various O-2-containing atmospheres (FeCoNiCrSi0.5 only). The two lower Si-content alloys contained an FCC single-phase structure, while the equimolar alloy had a BCC plus FCC dual-phase structure. The oxidation kinetics of all the alloys followed the parabolic rate law, with their oxidation rate constants increased with increasing temperature and decreasing Si content. In addition, the oxidation rate constants of the FeCoNiCrSi0.5 alloy steadily increased with increasing oxygen partial pressure, indicative of a typical oxide scale exhibiting a p-type semiconductivity. The scales formed on all the alloys consisted mostly of Cr2O3 and minor amounts of SiO2 (alpha-quartz). The oxidation mechanism of the HEAs is due primarily to outward diffusion of cations. (C) 2017 Elsevier B.V. All rights reserved.