Thermodynamics of Atomic Ordering in Cu-Zn-Al: A Monte Carlo Study

Abstract

We present a study of the short- and long- range ordering phenomena that take place in the bcc β phase of the ternary alloy Cu-Zn-Al. The results have been obtained by means of Monte Carlo simulations based on a three states Ising Hamiltonian. The evolution of the long- and short-range order degrees, internal energy, entropy and Helmholtz free energy are calculated as functions of temperature. The impact of short range order on the thermodynamics of the system is evaluated. The results obtained with the Monte Carlo technique are contrasted with those obtained within two different analytical approximations, whose validity is discussed. The calculated thermal variation of the specific heat near the long range ordering transitions is discussed and compared with experimental data.