STRUCTURE AND PROPERTIES OF TiAlN AND CrAlN COATINGS DEPOSITED BY SHORT-PULSE DUAL HIGH-POWER MAGNETRON SPUTTERING

Short-pulse high-power impulse magnetron sputtering (HiPIMS) provides the higher ionization of the sputtered material and the higher ion energy than other types of magnetron sputtering. In this work, short-pulse reactive HiPIMS in a dual magnetron configuration was used to deposit TiAlN and CrAlN coatings with different Al content on WC-Co substrates. For this purpose, asymmetric high-power bipolar pulses of 20-μs duration were applied to Ti and Al or Cr and Al targets to obtain coatings of different compositions. The structure, mechanical, and tribological properties of both TiAlN and CrAlN coatings were investigated. The results showed that the coatings had high hardness (up to 30 GPa) and wear resistance (wear rate of 10-8-10-9 mm3 N-1 m-1). Unlike wear resistance, hardness is weakly dependent on Al content. It is believed that the high average ion current densities and energy fluxes achieved in short-pulse dual HiPIMS are responsible for the improvement in both the mechanical and tribological properties of the nitride coatings. These results may indicate the potential applications of short-pulse dual HiPIMS as an alternative to cathodic arc evaporation for the deposition of hard nitride coatings.