Effect of C additions to the microstructure and wear behaviour of CoCrFeNi high-entropy alloy

CoCrFeNi high entropy alloys (HEAs) suffer from inferior hardness and low wear resistance. The introduction of hard particles is a common strategy to improve the tribological properties of this kind of alloy. However, the influence of carbide type (M23C6, M7C3, and M3C2) and its volume fraction on w...

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Bibliographic Details
Published inWear Vol. 530-531; p. 205032
Main Authors Zhang, Zeling, Ling, Yanfang, Hui, Jia, Yang, Fei, Zhang, Xuhai, Tan, Shuyong, Xie, Zonghan, Fang, Feng
Format Journal Article
LanguageEnglish
Published Elsevier B.V 15.10.2023
Subjects
CoCrFeNi
high entropy alloys (HEA)
M23C6 precipitation
Microstructure
Wear resistance
high entropy alloys (HEA)
M23C6 precipitation
Wear resistance
CoCrFeNi
Microstructure
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Summary:CoCrFeNi high entropy alloys (HEAs) suffer from inferior hardness and low wear resistance. The introduction of hard particles is a common strategy to improve the tribological properties of this kind of alloy. However, the influence of carbide type (M23C6, M7C3, and M3C2) and its volume fraction on wear resistance is still under debate. In this work, (CoCrFeNi)100-XCX (x = 0, 1.3, 1.7, 3.5, and 5.4 at. %) HEAs were prepared by vacuum arc melting. M23C6 precipitated in the FCC matrix through a subsequent heat treatment process. The effect of carbon additions on the microstructural evolution and wear behavior of (CoCrFeNi)100-XCX HEAs was investigated by dry sliding experiments with Al2O3 ceramic balls as counterparts. The results show that the C interstitials increased the lattice constant of the FCC matrix, on the other hand, the size and volume fraction of carbide precipitates increased with the carbon content. The Cr23C6 precipitates appeared at the grain boundaries and interdendritic regions, which is believed to help strengthen the alloy, leading to an increase in its hardness and wear resistance. However, when the C content is greater than 0.28 wt %, the wear rate went up due to the poor toughness and severe three-body abrasive wear. •M23C6 carbide reinforce CoCrFeNi high entropy alloys (HEAs) were prepared.•The hardness of the HEAs increased with the carbon content.•(CoCrFeNi)98.7C1.3 HEA exhibited the lowest friction coefficient and wear rate.
ISSN:0043-1648
1873-2577
DOI:10.1016/j.wear.2023.205032