Ab initio calculated binodal and spinodal of cubic Ti1-xAlxN - art. no. 071922

During annealing, metastable NaCl-structured (c) Ti1-xAlxN films initially exhibit spinodal decomposition which results in age hardening. Based on ab initio calculations, we show that the chemical requirement for spinodal decomposition in the quasibinary c-TiN-c-AlN system is fulfilled over a wide composition and temperature range. The enthalpy change for the decomposition of c-Ti0.34Al0.66N is similar to 26.4 kJ mol(-1), which is in good agreement with previously reported experiments. The obtained results enable materials design of Ti1-xAlxN-based coating systems for high-temperature applications.