The heat capacity in two-phase regions and the heat of phase transformations of some alloys in Zr-Nb and Zr-Sn systems

Abstract

Analytical expressions are given for the phase boundaries of diagrams of state for Zr-Nb and Zr-Sn systems. Thermodynamically justified temperature dependences of heat capacity of Zr-1% Nb, Zr-2.5% Nb, Zr-1.5% Sn, and Zr-2.5% Sn alloys in two-phase regions are given and recommended for use. The heats of second-order phase transformations α(Zr) ⟺ β(Zr) in alloys of Zr-Nb and Zr-Sn binary systems are obtained, and the heats of monotectoid reaction α(Zr)+β(Nb) ⟺ β(Zr) in the Zr-Nb system and of peritectoid reaction β(Zr)+Zr4Sn ⟺ α(Zr) in the Zr-Sn system are calculated.