Tailoring M7C3 carbide via electron work function-guided modification

M7C3 carbide [M: metallic element] is the primary reinforcement in white cast irons. Further improving its properties for maximized benefits is highly desired. However, no clear clues are available to guide the modification. Through atomic force microscopy in-situ analysis and first-principles calculations, we demonstrate that (Fe,Cr)(7)C-3 carbide's strength is governed by its metallic bond component. We theoretically prove that M7C3 carbide is tailorable by partially replacing its metallic elements with substitutes selected based on their work function as an indicator. This study provides an insight into the electronic origin of carbide's mechanical behaviour, helping guide developing high-performance M7C3 carbides. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study uses atomic force microscopy in-situ analysis and first-principles calculations to show that the strength of M7C3 carbide is governed by its metallic bond component. It also theoretically proves that M7C3 carbide can be tailored by partially replacing its metallic elements with substitutes selected based on their work function. This insight into the electronic origin of carbide's mechanical behavior helps guide the development of high-performance M7C3 carbides.