Effects of alloying elements on the generalised stacking fault energies of Pt: a first-principles study

ABSTRACT

By adding alloying elements in Pt, the solid-solution strengthening is extensively used to improve the mechanical properties of Pt-based alloys, one of the most promising high-temperature materials due to its higher melting point. Yet the microscopic mechanism of the alloying effects on the mechanical properties of Pt is unclear. Based on a systematic study of the influence of alloying elements on the generalised stacking fault energy (GSFE) of Pt with first-principles calculations, the alloying effects on deformation mechanism and ductility of Pt are explored in this study. It is found that the alloying elements such as Y, Hf, Mo tend to decrease the intrinsic stacking fault energy (${\gamma }_{isf}$) of Pt and improve its ductility, while Ru, Rh, Ir tend to increase the ${\gamma }_{isf}$ and result in brittleness. The analysis of the electron localisation function (ELF) and density of states (DOS) indicates that the weaker or enhancer bonding between Pt atom and alloying atom at the local stacking fault area is responsible for the variation of the GSFEs, which further affects the mechanical properties of Pt-based alloys.

KEYWORDS:

• Pt-based alloys
• generalised stacking fault energy
• alloying effect
• ductility
• first-principles calculations

Acknowledgements

This work was supported by National Natural Science Foundation of China (No.11772043), and Major Science and Technology Project of Precious Metal Materials Genetic Engineering in Yunnan Province (No. 2019ZE001-1, 202002AB080001, 2018IC058).

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No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

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Funding

This work was supported by National Natural Science Foundation of China [No. 11772043], and Major Science and Technology Project of Precious Metal Materials Genetic Engineering in Yunnan Province (No. 2019ZE001-1, 202002AB080001, 2018IC058).