Microwave vacuum sintering of FeCoNi1·5CuB0·5Y0.2 high-entropy alloy: Effect of heat treatment on microstructure and mechanical property. (November 2020)

• Record Type: Journal Article
• Authors: Wang, C.W.; Wang, H.M.; Li, G.R.; Liu, M.; Zhang, D.; Wen, H.R.; Ren, W.X.; Gao, L.P.; Chen, J.J.
• Is Part Of: Vacuum. Volume 181(2020)
• Publication Date: 2020-11
• Subjects: High-entropy alloy -- Microwave vacuum sintering -- Heat treatment -- Microstructure -- Mechanical property; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2020.109738
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: Face-centered-cubic (FCC) type high-entropy alloys (HEAs) exhibit outstanding ductility, but their performance is still inferior to body-centered-cubic (BCC) type HEAs, limiting its structural applications. The addition of boron (B) has effectively improved the strength, but it induces severe embrittlement because of the formation of M3 B (M = Fe, Co, Ni) borides. In this paper, FeCoNi1·5 CuB0·5 Y0.2 HEA was obtained by high-energy ball milling and microwave vacuum sintering process. Besides, the effects of annealing temperature on microstructural and mechanical properties were investigated. The specimen annealed at 950 °C exhibited moderate grain growth, and copper (Cu) precipitated in the FCC solid solution at 900 °C. The hexagonal close-packed (HCP) phase was piled up in blocks, and particles of YB6 -type precipitated. Overall performance improvement of the material was the greatest by annealing at 1050 °C. Highlights: FeCoNi1.5 CuB0.5 Y0.2 high-entropy alloy was obtained by high-energy ball milling and microwave vacuum sintering process. After annealing at 900 °C, fine particles related to Cu element precipitated on the surface of the FCC phase. The previous criteria cannot effectively predict the phases formation of the FeCoNi1.5 CuB0.5 Y0.2 high-entropy alloy. Nanoindentation was used to analyze on the mechanical properties of different phases.