Thermal stability of Al–Cr–N hard coatings

Heat treatment of arc-evaporated cubic Al0.7Cr0.3N hard coatings in Ar up to 1450 °C causes precipitation of AlN. The Cr-enriched matrix transforms into Cr via Cr2N under N2 release. These reactions are investigated by simultaneous thermal analysis, mass spectrometry, X-ray diffraction, and analytical transmission electron microscopy.