Exploring the alloying effects on generalized stacking fault energy and ideal strength of Ni and Ni3Al phases in Ni-based superalloys. (February 2022)

• Record Type: Journal Article
• Authors: Xia, Fangfang; Xu, Weiwei; Shi, Zhenchuan; Xie, Wei; Chen, Lijie
• Is Part Of: Mechanics of materials. Volume 165(2022)
• Publication Date: 2022-02
• Subjects: Ni-based superalloys -- Alloying effects -- Generalized stacking fault energy -- Ideal strength -- First-principles calculations; Strength of materials -- Periodicals; Mechanics, Applied -- Periodicals; Résistance des matériaux -- Périodiques; Mécanique appliquée -- Périodiques; Mechanics, Applied; Strength of materials; Periodicals; Electronic journals; 620.11
• DOI: 10.1016/j.mechmat.2021.104183
• Languages: English
• ISSNs: 0167-6636

Abstract

Abstract: To clarify the different effects of alloying elements on the strength of Ni and Ni3 Al, this study employs First-principles methods to investigate the effects of refractory elements Re, Ru, Ta, Mo and W on the generalized stacking fault energy and ideal strength of Ni and Ni3 Al, respectively. The results reveal that the alloying elements Re, Ru, Ta, Mo, and W can help to improve the creep strength of Ni but reduce that of Ni3 Al. Among these alloying elements, Re and Ru are more helpful for improving the strength of Ni, and for Ni3 Al, Ru has the weakest enhancing effect on the strength of Ni3 Al. Moreover, except for Ru, other alloying elements have more significant enhancing effects on the strength of Ni3 Al. The electronic structure analysis shows that the d orbitals of alloying elements except Ru can form deep and wide pseudogap near the Fermi energy level, which causes the obvious enhancement of the strength of Ni3 Al. Furthermore, the regular areas of charge distribution between atom Ru and its nearest neighbor atoms Ni are more vulnerable to be destroyed, resulting in Ni3 Al–Ru owning a relatively lower ideal tensile strength and reaches its ideal tensile strength under a smaller strain. Highlights: Re, Ru, Ta, Mo and W can help to improve the creep strength of Ni, but reduce that of Ni3 Al. Re, W, Mo, and Ta have more significant enhancing effects on the mechanical strength of Ni3 Al, compare with that of Ni. The d orbitals of Ru cannot form deep and wide pseudogap near the Fermi energy level, as other elements do.