Comparative study of TiAlN coatings deposited by different high-ionization physical vapor deposition techniques

In physical vapor deposition (PVD), the energy and incident angle of ions can be adjusted easily by applying an electromagnetic field so that coatings with different structures and properties can be produced. In this work, several high-ionization coating techniques are employed to deposit TiAlN coatings to compare the effectiveness of each technique and resulting coating properties. The continuous high-power magnetron sputtering (C-HPMS) technique shows advantages in the deposition rate and coating performance. In addition, a deposition rate of 400 nm/min is achieved by C-HPMS, whereas those of high power impulse magnetron sputtering (HiPIMS) and arc ion plating (AIP) are 85 nm/min and 225 nm/min, respectively. The coating also shows a particle-free and dense morphology with a smaller surface roughness of 22.4 nm. Owing to efficient ionization, the TiAlN coating deposited by C-HPMS has a high hardness of 33.2 GPa which is comparable to those prepared by AIP and HiPIMS but with small residual stress. The results provide valuable information on how to choose the proper techniques and parameters to produce coatings with the desirable adhesion strength, tribological properties, as well as corrosion resistance.