The different influences of the two incorporation sites of B atoms on the mechanical and thermodynamic properties of B2-ZrCu compounds: a first-principle calculation

摘要

We applied a first-principle calculation to investigate the different influences of the two incorporation sites of B atoms on the mechanical and thermodynamic properties of the near-equiatomic B2-ZrCu compound. The alloying B atoms have two possible incorporation sites, namely, octahedral interstices and Cu sites. When the concentration of B atoms is lower than 5.882 at., interstitial B atoms will be effective at improving the bulk modulus (B), shear modulus (G) and Young's modulus (E) of the B2-ZrCu parent. When the concentration of the substitutional B atoms is lower than 12.5 at., the ductility of the parent will be strengthened. The interstitial B atoms that are located at octahedral interstices in the 110 direction can remarkably improve the Debye temperature (Theta(D)) of the substituted Zr8Cu8-zBz phase. The prediction for the melting point shows that the high-temperature stability is strengthened with the increase of the B concentration. Interstitial B atoms are beneficial to the minimum thermal conductivity. Finally, the electronic properties are discussed in detail to further understand the mechanical properties.