Effects of alloying elements on the atomic structure, elastic and thermodynamic properties of L12-Co3(V, Ti) compound. (March 2022)

• Record Type: Journal Article
• Authors: Xi, Shengkun; Chen, Liuping; Bao, Longke; Han, Jiajia; Yu, Jinxin; Li, Zhou; Xu, Weiwei; Bin Deng, ; Wang, Cuiping; Liu, Xingjun
• Is Part Of: Materials today communications. Volume 30(2022)
• Publication Date: 2022-03
• Subjects: First-principles calculations -- Co-V-Ti-based superalloys -- Structural stability -- Mechanical properties -- Thermodynamic properties; Materials science -- Periodicals; 620.11
• DOI: 10.1016/j.mtcomm.2021.102931
• Languages: English
• ISSNs: 2352-4928

Abstract

Abstract: In this work, first-principles calculations were used to study the effects of alloying elements on the atomic structure, elastic property and thermodynamic property of L12 ordered γ′-Co3 (V, Ti) at finite temperature. Twenty transition metals (TM), including Sc, Cr, Mn, Fe, Ni, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Hf, Ta, W, Re, Os, Ir and Pt, have been considered as the alloying element at different crystallographic sites. The results show that Mn, Fe, Ru, Os, Rh, Ir, Ni, Pd, and Pt tend to occupy the Co site, while other elements prefer the Ti site of γ′-Co3 (V, Ti). In the ground state, all TMs except Cr, Mn, Fe, Y, Tc and Ru could stabilize the γ′-Co3 (V, Ti) compound, and the addition of Sc, Fe, Y, Rh, Pd, Ir and Pt can remain the compound a stable phase after involving its competitive phases. The mechanical property of TM-substituted γ'-Co3 (V, Ti) was found to be linearly related to both the value of the electron density and the molar volume of compound. However, at finite temperature, only Sc, Y, and Os enhance the thermodynamic stability of the γ'-Co3 (V, Ti) with the increasing temperature, which is different from the cases in the ground state. Graphical Abstract: ga1 Highlights: Properties of L12 ordered γ'-Co3 (V, Ti) were calculated at atomistic level using DFT method. Alloying effect of 20 elements to the phase stability and mechanical property of L12 phase was systematically studied. Anisotropy of mechanical property has been represented by 3D surface construction. Critical temperature of L12 phase has been predicted using Debye model.