TWO EQUATIONS OF STATE CONSIDERING THE THERMAL EFFECT FOR α, β AND ω PHASES OF ZIRCONIUM

Abstract

The Baonza and mGLJ equations of state (EOS) modified previously to consider the thermal effect are applied to study the thermodynamic properties of Zirconium (Zr) . It is proposed that the zero-point vibration term should be deleted in a thermal EOS, and the parameters cannot be directly taken as experimental data at a reference temperature, [Formula: see text] and [Formula: see text], but their values at absolute zero temperature, [Formula: see text] and [Formula: see text]. Based on the Einstein model, an approach is proposed to solve [Formula: see text] and [Formula: see text] from [Formula: see text] and [Formula: see text]. For the hcp (α phase), bcc (β phase) and hexagonal structure (ω phase) of Zr , the molar volume (V), isothermal bulk modulus (B) and thermal expansion coefficient (α) was calculated as a function of pressure and temperature. The predictive capabilities of the complete EOS are discussed and compared with experimental data.