The influence of Cr on He trapping behavior and the coupling effect of Cr/He on the mechanical behavior of the C14-Laves Fe2W phase: First–principle and quasi-harmonic approximation studies.

[Display omitted] • Cr influences the thermal properties of C14–Laves Fe 2 W phase. • Cr decrease the Gibbs energy and bulk modulus of C14–Laves Fe 2 W phase. • Cr increase the thermal expansion of C14–Laves Fe 2 W phase. • Cr and He can reduce the tensile strength aligning to [0001] of C14–Laves Fe 2 W phase. The influence of chromium (Cr) on the thermal properties of C14–Laves Fe 2 W phase were studied in detail based on the quasi–harmonic approximation. The effect of Cr on the helium (He) trapping behavior of the C14–Laves Fe 2 W phase was also investigated based on the defect formation energy with density functional theory (DFT). The results indicated that Cr could not only decrease the values of the Gibbs energy and bulk modulus of the C14–Laves Fe 2 W phase, but could also increase the thermal expansion coefficient of the C14–Laves Fe 2 W phase. In addition, Cr could reduce the capacity of the C14–Laves Fe 2 W phase to trap He. The coupling effect of Cr and He on the mechanical behavior of the C14–Laves Fe 2 W was studied, wherein both Cr and He could reduce the tensile strength that was aligned to the [0001] of C14–Laves Fe 2 W phase. The relation between the mechanical behavior of the C14-Laves Fe 2 W or Cr doped Fe 2 W phases and their thermal properties were also discussed. The fracture mechanisms of the C14–Laves Fe 2 W phases, with or without Cr/He–doping, along the (0001) grain plane was analyzed based on the charge density and partial densities of states (pDOS). [ABSTRACT FROM AUTHOR]