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First‐principles investigation of V‐doping effects on Fe 3 Cr 4 C 3 carbide in hypereutectic Fe–Cr–C hardfacing coating
Author(s) -
Shi Zhijun,
Shao Wei,
Xing Xiaolei,
Ren Xuejun,
Zhou Yefei,
Yang Qingxiang
Publication year - 2021
Publication title -
acta crystallographica section b
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.604
H-Index - 33
ISSN - 2052-5206
DOI - 10.1107/s2052520621006533
Subject(s) - materials science , carbide , ultimate tensile strength , doping , crystal structure , metallurgy , crystallography , chemistry , optoelectronics
The mechanical property improvement of M 7 C 3 carbides in hypereutectic Fe–Cr–C hardfacing coating is required for its widespread application and longer service life. Vanadium is a frequently used alloying element, while the effects of V doping on the stability and tensile properties of M 7 C 3 carbide have been rarely reported. In this article, the formation enthalpy, structural stability, anisotropic tensile properties and electronic structure of V‐doped M 7 C 3 (Fe 3 Cr 4 C 3 ) carbide were calculated by the first‐principles method. The mechanism by which the tensile property of Fe 3 Cr 4 C 3 carbide can be improved by V‐atom doping is discussed. The results show that the formation enthalpy (−0.24 eV/atom) of Fe 3 Cr 3 VC 3 carbide is lower than that (0.48 eV/atom) of Fe 3 Cr 4 C 3 carbide, which indicates that the formation of Fe 3 Cr 3 VC 3 carbide is more facile. The absence of an imaginary frequency in the phonon dispersion spectra reveals that the Fe 3 Cr 3 VC 3 carbide model is stable. Compared with Fe 3 Cr 4 C 3 carbide, the tensile strength of Fe 3 Cr 3 VC 3 carbide in the (0001) crystal face is increased from 44.42 to 48.46 GPa and that in the (11 1 1) crystal face is also increased, from 28.99 to 34.19 GPa. The reasons that the tensile property of Fe 3 Cr 4 C 3 can be improved by V doping are the electron redistribution and the formation of stronger bonds in Fe 3 Cr 3 VC 3 carbide.