Formulation for the prediction of melting temperature of metallic solids using suitable equation of states

Abstract

We presents expressions for the pressure dependence of the melting temperature of metals using Murnaghan, Usual-Taits, and Kholiya equations of state. The predicted model explains the corelation among the pressure, melting temperature, bulk modulus, its first pressure derivative and volume compression at zero pressure. The formalism is then applied to determine the Tm(P) of transition and noble metals such as Cu, Al, Zn, Au, Ag, Mn, Cd, and Mg, over a wide range of pressure up to 35 GPa. It is observed that the Murnaghan equation of state gives accurate result for the metals having higher bulk modulus thus having higher melting temperature. Kholiya equation of state shows closest result with the experimental data for those metals whose bulk modulus is decreasing continuously whereas the trend of variation is similar in Usual-Taits equation of state. The Usual-Taits equation of state, also referred to as the universal equation of state, exhibits the similar trend of variation. This study also sheds light in understanding the quantitative effect of pressure on melting temperature. Obtained results show good agreement with previous experiments and calculations thus justifying the validity of our model.