Thermodynamic Analysis of Al-Ni, Al-Cu Alloys System Using Calphad Method

Abstract

The CALPHAD technique, in conjunction with the PBIN database, is employed to conduct a thorough thermodynamic analysis and assessment of the binary alloy systems Al-Cu and Al-Ni. This study explores the thermodynamic properties, including phase diagrams, Gibbs free energies, and thermodynamic molar activities across the entire compositional range. The temperature maintained for assessment is 2000-2050 K. The doping characteristic of the AL-Ni binary system is more epitaxial and useful for doping industries. The correspondence of Raoult’s law is more precise in the Al-Ni binary alloy system due to its better doping characteristics. The entropy and the enthalpy of both systems increase. The greater decrease in the Gibbs curve and activity predicted the more stability of the alloying system Al-Ni. Within the Al-Ni system, a composition range of 0.4-0.6 mole percent at a temperature of 2050 K is identified as the most stable, contrasting with the Al-Cu system, which exhibits the least stability. The lattice vibrations mode and Brillion zone growth during alloying contribute to highly epitaxial characteristics, with pure and sharp attractive interactions among alloying elements. Negative deviation from ideality in activity is observed in the Al-Ni system, further supporting its increased stability. This is attributed to the lower Gibbs energy and higher enthalpy accordance. Both Al-Cu and Al-Ni binary systems show the highest level of equilibrium and stability. The enthalpy values of both alloying systems gradually increase with temperature. In the solid era of both binary alloy systems, Al-Cu and Al-Ni, the ferrite phase is identified as the stable phase. The most stable ferrite phase, capable of withstanding the highest temperatures, holds promise for applications in industrial sectors and materials metallurgy.