STRUCTURAL-PHASE STATUS OF HIGH ENTRICITY NbTiHfVZr ALLOY

Abstract

The paper presents the results of the high entropy alloy NbTiHfVZr stability study based on the analysis of critical Yum-Roseri indices, enthalpy of double alloys by Miedema method, entropy of mixing of NbTiHfVZr compound near the melting temperature. The method of inverse convex shells (InveseHubWeb) found temperature stability intervals, which for the compound NbTiHfVZr extend from the melting temperature to 1200K. In the case of NbTiHfZr the temperature stability interval extends up to room temperature. The obtained results indicate that the compounds NbTiHfVZr, NbTiHfZr belong to the high entropy lattices of which belong to the class of single-phase single-element solid solutions. Prediction of the lattices by the evolution code in the USPEX code made it possible to detect from the base of 300 standards, several simple cubic lattices with the spatial group P1 and different spatial distribution of atoms, which lattice energy turns out to be negative. The totality of the results obtained indicates that the found standards can be attributed to the stable phases in the corresponding temperature stability intervals of the compounds NbTiHfVZr, NbTiHfZr.