Thermodynamic analysis of the Al–Ni system

Abstract

The thermodynamic descriptions of the Al–Ni system from literature were reviewed and it was concluded that a thermodynamic re-assessment of the Al–Ni system focusing on the order-disorder transitions is necessary. The Al–Ni system was re-assessed in the present work using the order-disorder formalism to describe both B2 and L12 phases. To get a more accurate description of the L12 phase, thermodynamic constraints for the parameters of the L12 phase, which were often ignored, were applied during the thermodynamic assessment. The same constraints may be applied to the assessments of the other systems. Long-range ordering for the L12 phase and short-range ordering for the FCC_A1 phase have been discussed. The present work provides a quantitative description of the FCC_A1 and L12 phase equilibria of the important Ni-rich part of the system as well as improvements of some aspects of the Al-rich FCC_A1 phase. An improvement of the liquidus for the primary B2 phase was also obtained with fewer parameters.