Isotherm of Aluminum Based on the Generalized Equation for the Gruneisen Coefficient
S. D. Gilev
Lavrentyev Institute of Hydrodynamics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090 Russia
Keywords: Gruneisen coefficient, isotherm, cold compression curve, high pressure, smallparameter equation of state
Abstract
A method of constructing the curve of cold compression and the isotherm for the metal based on the generalized equation for the Gruneisen coefficient is considered. In contrast to available approaches, it is proposed to take into account the change in the character of interaction of atoms in the crystal due to compression. For this purpose, the dimensionless parameter t in the generalized equation is considered as a function of compression. The experimental data on metal compressibility testify that the parameter t increases with an increase in density. Free parameters of the model for aluminum are found. The proposed approach allows the aluminum isotherm to be described more accurately and in a wider range of density. For the cold compression curve, the working region of the model increases almost by an order of magnitude in terms of density and by more than two orders of magnitude in terms of pressure (as compared to the model where the parameter t is assumed to be constant).
