The Influence of Boron and Carbon Addition on the Glass Formation and Mechanical Properties of High Entropy (Fe, Co, Ni, Cr, Mo)-(B, C) Glassy Alloys

Coatings made from metallic glasses are a promising solution for protecting surfaces of materials in various challenging environments. From an engineering perspective, glassy alloy coatings containing carbon are of greater importance compared to those without carbon but containing boron. Despite anticipating improved coating characteristics, there is no data on using high entropy glassy alloy as a coating material. In this paper, we investigated the influence of the simultaneous addition of boron and carbon elements on the glass-forming ability, thermal stability, crystallization behavior, yield strength, hardness, and corrosion resistance of high entropy (Fe, Co, Ni, Cr, Mo)-(B, C) glassy alloys. It was found that the content of boron and carbon had a significant effect on the improvements of glass-forming ability, mechanical properties, and corrosion resistance. The (Fe0.25Co0.25Ni0.25Cr0.125Mo0.125)75(B0.7C0.3)25 bulk glassy alloy exhibits high glass-forming ability, high yield strength of 3500 MPa, Vickers hardness of 1240, and the highest corrosion resistance among the alloys. We also discussed the reason for their good engineering properties, and the possibility of using high entropy glassy alloys as coating materials, in addition to the guidelines for designing high-performance multicomponent glassy alloys.