Theoretical study of mechanical and thermodynamic properties of W–Fe alloys: Promising ultra-high temperature alloy materials

• Published in: Vacuum 2024-04, Vol.222, p.113047, Article 113047
• Main Authors: Zhang, Meiyun, Wang, Xunjie, Chen, Yun, Cai, Houdao, Li, Hongying, Jiang, Diyou
• Format: Article
• Language: English
• Subjects: Ductility; First-principles; High temperature alloys; Thermal conductivity; Thermal expansion; W-Fe alloys
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2024.113047

In this paper, three kinds of W–Fe alloy models are constructed, namely W15Fe1, W14Fe2 and W13Fe3 alloys. By investigating the phonon spectra, it is found that W13Fe3 alloy is thermodynamically unstable. Therefore, the mechanical and thermodynamic properties of W, W15Fe1 and W14Fe2 alloys are investigated based on first principles method. The investigation demonstrates that the bulk modulus of W15Fe1 alloy increases rapidly with increasing temperature, exhibits high-temperature alloy characteristics. However, the bulk modulus of W14Fe2 alloy decreases rapidly with increasing temperature, and is lower than that of W. The thermal expansion coefficient of W15Fe1 alloy decreases with increasing temperature, and is significantly lower than that of W at 1400K, exhibits low expansion behavior at high temperatures. The thermal expansion coefficient of W14Fe2 alloy increases rapidly with increasing temperature, and is obviously higher than that of W. The thermal conductivity of W15Fe1 alloy exceeds that of W at 2300K, which indicates that doping an appropriate Fe in W can improve the thermal conductivity of W at high temperatures. However, the thermal conductivity of W14Fe2 alloy is significantly lower than that of W and W15Fe1 alloy. At 0K, doping Fe in W decreases the mechanical strength of W, but improves its ductility. •The bulk modulus of W15Fe1 alloy increases rapidly with increasing temperature, exhibits high-temperature alloy characteristics.•The thermal expansion coefficient of W15Fe1 alloy decreases with increasing temperature, and is significantly lower than that of pure W at 1400K, exhibits low expansion behavior at high temperatures.•The thermal conductivity of W15Fe1 alloy exceeds that of W at 2300K, which indicates that doping an appropriate Fe in W can improve the thermal conductivity of W at high temperatures.•At 0K, doping Fe in W decreases the mechanical strength of pure W, but improves its ductility.•It is found that the adsorption energy of O is the smallest at the bridge site, which indicates that the bridge site is more sensitive to O adsorption.