INFLUENCE OF SUBSTRATE HEATING AND BIAS POTENTIAL ON THE Ti Al C N COATINGS OPTICAL CHARACTERISTICS

Abstract

Ti–Al–C–N coatings were produced by reactive magnetron deposition at different substrate temperatures Ts (220, 340 and 440 °C) and bias voltages Ubias (–90, –150 and –200 V). Using the energy dispersive X-ray spectroscopy method, it was found that the increase of the bias voltage led to a growth of argon atomic concentration and the (Al + Ti) / (Ti + N) ratio and to a decrease of the trace oxygen concentration in Ti–Al–C–N coatings. The growth of Ts promoted a decrease in the oxygen concentration. By means of scanning electron microscopy, a change in the type of the microstructure (columnar, granular and mixed columnar-granular) of coatings by varying Ts and Ubias was found. Electrophysical measurements showed the change of the film resistivity (1982–3169 μΩ · cm) when the deposition conditions were varied. The solar absorptance αs was varied from 0.24 to 0.54, the emittance ε was varied from 0.33 to 0.52, and the αs / ε ratio was varied from 0.60 to 1.44 by changing Ts and Ubias. The obtained results indicate the opportunity to vary the Ti–Al–C–N films electrophysical and optical characteristics by choosing optimal substrate heating temperature and bias voltage.