Cr2N0.62-11Ag nanocomposite coatings containing 11 wt.% of Ag solid lubricant were deposited on substrates made of Cr-V ledeburitic tool steel Vanadis 6 by reactive magnetron sputtering at a deposition temperature of 500 °C. The experiments consisted of long term annealing up to 24 h at temperatures of 300, 400 and 500 °C, respectively, in closed-air atmosphere. The structural changes after annealing were evaluated by Auger electron spectroscopy (AES) and scanning electron microscopy (SEM). As a result of silver diffusion, the highest population density of silver particles on coating surfaces has been detected after 0.5 h and 4 h annealing at temperatures of 400 °C and 300 °C, respectively. Beyond the maximum peak, the population density of silver particles decreased with increasing the annealing time. Moreover, during annealing at temperature of 500 °C, very low population density was observed through all annealing process. This phenomenon was explained by sublimation of very small silver particles (less than 20 nm) and also by oxidation of coating surface, which was detected mostly during annealing at 500 °C. The oxide layer seems to be effective as a barrier of silver diffusion. The annealing of the films at temperatures below the deposition temperature induced limited both silver diffusion and depletion of silver within coating matrix.Keywords: Chromium nitride, silver, magnetron sputtering, annealing, auger electron spectroscopy
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