Thermal stability and mechanical properties of arc evaporated ZrN/ZrAlN multilayers

ZrN1.20/Zr-0 44Al0.56N1 (20) multilayer films as well as ZrN1 (17) and Zr0 44Al0 N-56(1.20) films were deposited by reactive arc evaporation on WC-Co substrates Samples were post-deposition annealed for 2 h at 800-1200 C As-deposited and heat treated films were characterized by scanning transmission electron microscopy X-ray diffraction and nanoindentation The thermal stability was studied using a combination of differential scanning calorimetry thermogravimetry and mass spectrometry The as-deposited Zr0 44Al0 56N1.20 film exhibits a nanocomposite structure of cubic and wurtzite ZrAlN During annealing the formation of ZrN- and AlN-rich domains results in age hardening of both the Zr0 44Al0.56N1.20 and the ZrN/ZrAlN multilayers The age hardening is enhanced in the ZrN/ZrAlN multilayer due to straining of the ZrAlN sublayers in which a maximum hardness of 31 GPa is obtained after annealing at 1100 degrees C (C) 2010 Elsevier B V All rights reserved