Effect of osmium substitution on structural, electronic, mechanical, and thermodynamic properties of W–Os alloys: A first-principles study

• Published in: Journal of materials research 2023-02, Vol.38 (3), p.883-893
• Main Authors: Chen, Yun, Tang, Lu, Cai, Houdao, Zhang, Meiyun, Wang, Xunjie, Jiang, Diyou
• Format: Article
• Language: English
• Subjects: Anisotropy; Applied and Technical Physics; Biomaterials; Chemistry and Materials Science; Crystal lattices; Cubic lattice; Doping; Enthalpy; First principles; Inorganic Chemistry; Lattice parameters; Materials Engineering; Materials research; Materials Science; Mechanical properties; Nanotechnology; Osmium; Stiffness; Thermodynamic properties; Thermodynamics; Tungsten base alloys
• ISSN: 0884-2914; 2044-5326
• DOI: 10.1557/s43578-022-00874-x

In this paper, four W–Os alloys are designed, namely W 0.9375 Os 0.0625 , W 0.875 Os 0.125 , W 0.8125 Os 0.1875 , and W 0.75 Os 0.25 alloys. Based on the analysis of the formation enthalpy and phonon spectrum, the W 0.8125 Os 0.1875 and W 0.75 Os 0.25 alloys are thermodynamically unstable. Therefore, this paper only studies the mechanical and thermodynamic properties of pure W, W 0.9375 Os 0.0625 , and W 0.875 Os 0.125 alloys. The results show that W 0.9375 Os 0.0625 and W 0.875 Os 0.125 alloys still keep the cubic crystal system, and the lattice constants of pure W are reduced by doping Os. Based on the mechanical parameter analysis, the doping of Os reduces the stiffness of pure tungsten, but improves its strength. The B / G ratios of W 0.9375 Os 0.0625 and W 0.875 Os 0.125 alloys are higher than that of pure W, which indicates that Os doping can increase the ductility of pure tungsten. The W 0.875 Os 0.125 alloy has anisotropic characteristics. However, the W 0.9375 Os 0.0625 alloy has isotropic characteristics, which also shows that Os doping can improve the anisotropy of pure tungsten. Graphical abstract