The structure and toughness of TiN coatings prepared by modulated pulsed power magnetron sputtering

Titanium nitride (TiN) coatings were prepared on different substrates (Si wafer, M2 steel, glass) by modulated pulsed power (MPP) sputtering and continuous dc magnetron sputtering (dcMS). The structure and properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), nanoindentation and the Vickers indentation test. It was found that the structure was transformed from the columnar growth to the branched growth as the peak target current density (Id) increased to 0.4 A/cm2. The results of plasticity index δH and microindentation crack showed the toughness was improved. MPP TiN coating could withstand the maximum load of 4.9 N when microindentation crack was first discovered at 0.4 A/cm2 while 0.49 N at 0.02 A/cm2 in dcMS condition. This indicated that the high ion flux bombardment of the MPP plasma could be applied to change the structure and toughen TiN coatings.