Experimental investigation and thermodynamic calculation in the Al–Be–Si ternary system

Abstract

Abstract A thermodynamic optimization for the Be– Si system has been performed using the CALPHAD (CALculation of PHAse Diagrams) technique applied to newly measured phase diagram data. The description for this binary system is then combined with the thermodynamic parameters in the Al –Be and Al –Si systems to synthesize a thermodynamic description for the Al –Be –Si ternary system. To verify the reliability of the extrapolated ternary phase diagrams, 11 decisive ternary alloys are prepared by are melting Al, Be and Si pieces and annealing at 530 °C for 8 days. Water-quenched samples are analyzed using differential thermal analysis (DTA), X-ray diffraction (XRD), optical microscopy, and scanning electron microscopy with energy dispersive X-ray (SEM/EDX) techniques. The calculated isopleths at 94 wt.% Al, 88 wt.% Al, 50 at.% Al, and 2 wt.% Be are compared with the experimental data from the present work and the literature. The comparisons show that no ternary interaction parameter is needed for the ther-modynamic description of this ternary system. The liquidus projection and reaction scheme are also presented.