Theoretical investigations of solid-solution effect on the twinning of Ni. (October 2019)

• Record Type: Journal Article
• Authors: Xia, Fangfang; Xu, Weiwei; Gang, Tieqiang; Wang, Wei; Chen, Lijie
• Is Part Of: Journal of physics and chemistry of solids. Volume 133(2019)
• Page Start: 1
• Page End: 6
• Publication Date: 2019-10
• Subjects: Ni-based superalloys -- Solid-solution effect -- First-principles method -- Generalized stacking fault energy -- Twinning; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2019.04.030
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: In terms of first-principles method, the influences of Co, Cr, Fe, Ta, Mo and W atoms on the generalized stacking fault energy of Ni are investigated. The bridge between stacking fault energy and twinning is comprehensively constructed by various previous criterions. Our calculation results indicate that the addition of Mo has the maximum positive effect on the twinning of Ni, while Cr shows the minimum effect. The ranking sequence of twinning abilities can be drawn as: Ni-Mo > Ni-Fe ≈ Ni-Ta > Ni-W > Ni-Co > Ni > Ni-Cr. On the other hand, the addition of Fe or Ta significantly reduces the intrinsic stacking fault energy of Ni, which is beneficial to obtain the dislocation glide during deformations. Based on the analysis of charge density, the bonding characteristics near the fault plane are observed to reveal the electronic redistribution during the slipping. It is found that the intrinsic stacking fault configuration and double-layers twin configuration reconstitute stable bonds near the fault plane corresponding to two valley points of the GSFE curve, while these bonds will be disrupted under a series of displacements. Highlights: Generalized stacking fault energies (GSFEs) of Ni are calculated with the addition of solid-solution atoms. Influences of the solid-solution elements on the twinning of Ni are qualitatively and quantitatively analyzed. Ranking sequence of twinning abilities can be drawn as: Ni-Mo > Ni-Fe ≈ Ni-Ta > Ni-W > Ni-Co > Ni > Ni-Cr. Intrinsic stacking fault configuration and double-layers twin configuration reconstitute stable bonds near fault plane.