The Al-Ti-N films deposited by multi-arc ion plating have been annealed in vacuum within the range of 700-1100 degrees C. X-ray diffraction results showed that the structure of the films underwent the formation of coherent c-TiN and c-AlN for the annealing temperatures were up to 900 degrees C. A new phase AlTix (x = 0.50, 0.56, 3) was observed after annealing. The X-ray photoelectron spectroscopy results showed the intensity of Ti-Al bonds decreased as annealing temperatures increased, indicating the decomposition of (Al, Ti)N into c-TiN and c-AlN were at the expense of Ti-Al bonds. Differential scanning calorimetry experiments were used to investigate the dynamic behavior of the films during annealing process and the results showed that the N-2 formed as a consequence of the phase transformation process. The release of the N-2 resulted in the peeling of the films from the substrates. The film exhibited a maximum hardness of 39 GPa after 900 degrees C annealing due to the formation of coherent c-TiN and c-AlN phases. In addition, we also investigated the influence of vacuum annealing on adhesive strength. (C) 2013 Elsevier B.V. All rights reserved.