Effect of Cu segregation on the phase transformation and properties of AlCrFeNiTiCux high-entropy alloys. (January 2022)

• Record Type: Journal Article
• Authors: Huang, Lei; Wang, Xuejie; Huang, Baoxu; Zhao, Xingchuan; Chen, Hui; Wang, Changzheng
• Is Part Of: Intermetallics. Volume 140(2022)
• Publication Date: 2022-01
• Subjects: B. phase transformation -- A. high-entropy alloys -- D. segregation -- G. wear-resistance -- B. corrosion; Intermetallic compounds -- Metallography -- Periodicals; Metallic glasses -- Periodicals; Composés intermétalliques -- Métallographie -- Périodiques; 669.94
• DOI: 10.1016/j.intermet.2021.107397
• Languages: English
• ISSNs: 0966-9795

Abstract

Abstract : In this work, the effect of Cu on the phase transformation, microstructure, and properties of AlCrFeNiTiCux high-entropy alloys (HEAs) was investigated. Meanwhile, the formation mechanism of the FCC solid solution was discussed. The results showed that it was a beneficial effect on the formation of the FCC solid solution for the addition of Cu into HEAs from the perspective of valence electron concentration (VEC), enthalpy of mixing (ΔHmix ) and difference in atom size (δ), which was confirmed by X-ray diffraction and Scanning Electron Microscope analysis. In addition, the increment of Cu content in the alloys promoting the segregation of Al, Ni and Ti in dendrite and Fe, Cr segregated into particles distributed in dendrite and inter-dendrite. The micro-hardness of the HEAs decreased with increasing Cu content and as the Cu content increased, oxidative wear intensified. However, the friction coefficient was significantly reduced, which was related to the lubricity of Cu itself. Besides, the segregation of Cu increased the corrosion current density of the passivation zone of the HEAs, thereby reducing the corrosion resistance of the HEAs in 0.5 mol/L H2 SO4 solution. Highlights: Added Cu promotes FCC phase forming. Cu improves the wear resistance. Cu element reduces the corrosion resistance.