Optimization on mechanical properties of Fe7-xCrxC3 carbides by first-principles investigation

A serious investigation of Fe7-xCrxC3 carbides were performed based on first-principles calculations. Alloy element Cr can enhance the structural stability of Fe7-xCrxC3 carbides. Among Fe3C and Fe7-xCrxC3 carbides, Fe4Cr3C3, which shows a higher elastic moduli, is potentially a high-strength and hard material, possessing a ductile property interestingly as well. Calculated hardness of Fe4Cr3C3 is higher than other carbides which are consistent with the current experiments. Electronic structures show that Fe7-xCrxC3 carbides have complex mixture of metallic, covalent, and ionic characters. (c) 2013 Elsevier B.V. All rights reserved.