Effect of Zr concentration on the mechanical and thermodynamic properties of NbIr₃ intermetallic compounds from theoretical estimations

ABSTRACT

The iridium is an important metal which has excellent resistance to corrosion at high temperature. L1₂ intermetallic compounds i.e. Ir₃Nb and Ir₃Zr, with similar lattice parameters are ideal for working at high temperature. They are fully soluble due to their low lattice misfit. A first-principle investigation into the effect of doping Zr with different concentrations on the electronic structure, mechanical and thermodynamic properties of NbIr₃ has been studied to prompt the development of novel high-temperature materials. Nine Zr_xNb_8−xIr₂₄ compounds are carefully considered. The results show that adding Zr into these compounds can strengthen their structural stability and ductility. Nevertheless, it reduces the elastic modulus and elastic stiffness. Simultaneously, with the increase of Zr content, the thermodynamic properties of these compounds decrease. It is also found that the changes of elastic modulus are mainly attributed to the variations of bonds in these compounds.

KEYWORDS:

• L1₂ Ir–Nb–Zr compounds
• mechanical properties
• thermodynamic properties
• first principles

Disclosure statement

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

Additional information

Funding

This research work is supported by the Guangxi Natural Science Foundation [grant number 2018GXNSFDA050008], the National Natural Science Foundation of China [grant number 51761002], the National Key R&D Program of China [grant number 2016YFB0301400], the Training Plan of High-Level Talents of Guangxi University [grant number XMPZ160714], and the research project of Guangxi Key Laboratory of Processing for Non-ferrous Metallic and Featured Materials [grant number GXYSSF1807]. The high-performance computing platform of Guangxi University is appreciated.