Microstructure and Mechanical Properties of CoCrFeNiSix (x = 0, 0.25, 0.5, 0.75) High-Entropy Alloys Based on Powder Plasma Arc Additive Manufacturing

• Published in: Journal of materials engineering and performance 2024-11, Vol.33 (22), p.12413-12423
• Main Authors: Luo, Jinle, Wang, Jiankun, Su, Chuanchu, Geng, Yanfei, Chen, Xizhang
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Corrosion and Coatings; Engineering Design; Materials Science; Original Research Article; Quality Control; Reliability; Safety and Risk; Tribology
• ISSN: 1059-9495; 1544-1024
• DOI: 10.1007/s11665-023-08830-4

CoCrFeNi high-entropy alloy (HEA) has the characteristics of high plasticity and low strength, which limit its application and development. In this study, a novel powder plasma arc additive manufacturing technique was used to prepare CoCrFeNiSi x ( x  = 0, 0.25, 0.5, 0.75) HEAs. By using scanning electron microscope, x-ray diffractometer, electron backscattered diffraction, hardness tester and tensile tester, we analyzed the effect of Si element on the phase structure, microscopic morphology, hardness and tensile properties. The results show that CoCrFeNiSi x HEAs are composed of face-centered cubic (FCC) structure and the second phase (rich Ni and Si). The volume fraction of the second phase increases significantly with increasing Si content, while the grain size of the alloy decreases. The addition of Si markedly improved the hardness (160-454 HV) and yield strength (165.38-354.43 MPa) of the alloys, but the formation of the precipitated phase led to a decline in elongation (55.87-1.43%). These results provide a systematic understanding of the phase formation and mechanical properties of CoCrFeNiSi x HEAs.