Phase equilibria in the Al-C-Ni-W quaternary system

Based on a critical literature review, the Al-C-Ni and C-Ni-W ternary systems are thermodynamically reassessed using the CALPHAD (CALculation of PHAse Diagrams) method. The calculated phase equilibria and thermodynamic properties can well reproduce the experimental data. The Al-C-Ni-W thermodynamic database is then established using descriptions of the accepted ternary systems. The calculated solubility of WC in AINi(3) is in good agreement with the experimental result. The computed solubility is used to describe the hardness-solubility dependence along the WC-AlNi3 section according to the solid solution strengthening mechanism. The effect of substitution of Co by Ni and AlNi3 as the binder phase on the phase relations in the WC-based cemented carbides is also investigated using the present thermodynamic parameters. Good agreement between calculated and experimental results indicates that the current thermodynamic database could provide an efficient guidance for designing and developing innovative WC-AlNi3 cemented carbides. (C) 2014 Elsevier Ltd. All rights reserved.