Complexions and grain growth retardation: First-principles modeling of phase boundaries in WC-Co cemented carbides at elevated temperatures

WC-Co cemented carbides combine superb hardness with high toughness making them ideal for usage in metal machining and wear resistant tools. Controlling the WC grain size is important during sintering as plays a crucial role mechanical properties of material. Experimental studies have observed different growth rates morphologies W-rich C-rich materials, but mechanism behind this has not been clarified. Here, we consider possibility an interface-stabilized state, complexion, at WC/Co phase boundary carbides, namely thin films cubic structure. An interfacial diagram derived using ab-initio calculations first-principles modeling. Cluster expansions are employed to model carbon vacancies Monte Carlo simulations sample configurational entropy. Force-constant fitting used extract harmonic free energy ground-state structures effects from anharmonicity electronic excitations effectively incorporated companion study on bulk phases. We predict stabilization liquid temperatures only conditions. This consistent experimental findings where stacking predominantly materials. use knowledge suggest explanation carbides.