THE INFLUENCE OF CP(L-S) ON THE CALCULATION OF PHASE-DIAGRAMS - THE SYSTEMS AL-CA AND CA-PB

The difference in heat capacity, Cp(L)-Cp(s), between liquid and solid influences greatly the calculation of phase diagrams. We show, that irrespective of how we represent the difference in Gibbs energy between liquid and solid, G(L-s), the results are the same: the Enthalpy of formation of the binary intermediate compounds, and the value of G(L-s) of the end components at their eutectic point is the same. We show this on the two binary systems Al-Ca and Ca-Pb. Inthe Al-Ca system the Ca eutectic temperature is 300 K below its melting point.