Temperature dependence of the residual stresses and mechanical properties in TiN/CrN nanolayered coatings processed by cathodic arc deposition

Nanolayered TiN-CrN coatings were synthesized by cathodic arc deposition (CAD) on M2 tool steel substrates. The aim of this study was to establish a double-correlation between the influence of the bilayer period and the deposition temperature on the resulting mechanical-tribological properties. The superlattice hardening enhancement was observed in samples deposited at different temperatures - i.e. without additional heating, 300 degrees C and 400 degrees C Nonetheless, the residual compressive stresses are believed to be the responsible for reducing the hardness enhancement when the deposition temperature was increased. For instance, sample deposited without additional heating presented a hardness of 48.5 +/- 1.3 GPa, while by increasing the processing temperature up to 400 degrees C it was reduced down to 31.2 +/- 4.1 GPa due to the stress relaxation. Indeed, the sample deposited at low temperature which possesses the thinnest bilayer period (13 nm) exhibited better mechanical properties. On the contrary, the role of the interfaces introduced when the period is decreased seems to rule the wear resistance. (C) 2013 Elsevier B.V. All rights reserved.