Enhanced strength without sacrificing ductility in FeCrMnVSix high entropy alloys via controlling the ratio of metallic to covalent bonding. (January 2023)

• Record Type: Journal Article
• Authors: Liu, Yanyan; Yao, Zhongping; Zhang, Peng; Lin, Shouyuan; He, Mingyu; Lu, Songtao; Wu, Xiaohong
• Is Part Of: Materials & design. Volume 225(2023)
• Publication Date: 2023-01
• Subjects: High entropy alloys -- First-principles calculation -- Strength and ductility -- Tribological properties; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2022.111565
• Languages: English
• ISSNs: 0264-1275

Abstract

Graphical abstract: Highlights: The ELF and DOS calculations confirm that the orbitals of Si and FeCrMnV overlap and thus form covalent bonds. Computational and experimental results show that addition of Si enhances the elasticity and hardness of FeCrMnVSi x HEAs. FeCrMnVSi x HEAs have enhanced strength without sacrificing ductility due to the covalent bonding created by the Si atoms. The Si-containing HEAs coatings exhibited excellent tribological properties. Covalent bonding contributes to strength and metallic bonding facilitates ductility. Abstract: It has been the pursuit of materials science to enhance strength without sacrificing the ductility of a material. By introducing the semi-metallic Si into the FeCrMnV high-entropy alloy (HEA) to control the ratio of metallic and covalent bonding, we obtained a FeCrMnVSi x HEAs with high strength and favorable ductility from the perspective of interatomic bonding. First-principles calculation was employed to calculate the structural model, electronic environment, and mechanical properties. The theoretical calculations demonstrated that the covalent bonding had been obtained in the FeCrMnV HEA consisting of metallic bonding due to the addition of Si. Under the guidance of theoretical calculation, FeCrMnVSi x HEAs were successfully prepared by laser cladding on 1Cr13 steel substrate. The nanoindentation, Vickers microhardness, and tensile tests were performed, and the results indicated that the strength of HEA was enhanced without sacrificing ductility. In addition, the as-prepared Si-containing HEA coatings exhibited excellent tribological properties. The mechanism of simultaneous formation of metallic and covalent bonds on the mechanical properties was analyzed. The enhanced strength without sacrificing ductility in FeCrMnVSi x HEAs is attributed to the proper combination of metallic and covalent bonding, the metallic bonding facilitates favorable ductility while the covalent bonding contributes to excellent strength.