The effect of magnetic field configuration on structural and mechanical properties of TiN coatings deposited by HiPIMS and dcMS

Abstract

The quality of coatings deposited by magnetron sputtering is known to depend on, among others, the magnetic field strength (Φ) and the magnetic field configuration. Furthermore, high power impulse magnetron sputtering (HiPIMS) is known to result in low defect - high density coatings, and is therefore used to deposit barrier coatings against wear and corrosion. The influence of varying the Φ, on deposition rate (R), structure and hardness of titanium nitride coatings prepared by HiPIMS and dc magnetron sputtering (dcMS) was investigated. At 22mT, the ratio between HiPIMS deposition rate and dcMS deposition rate (RHiPIMS/RdcMS) was almost equal to 1. As Φ was increased from 22mT to 35mT, R decreased by 28% for HiPIMS and increased by 15.6% for dcMS, and RHiPIMS/RdcMS was reduced from 1 to 0.63. From 35mT to 44mT, the decrease in R slowed to 6% for HiPIMS and to 12.5% for dcMS. The (111) orientation was dominant over (200) orientation for both HiPIMS and dcMS, and become less dominant with the Φ in the case of dcMS. The residual stresses and surface roughness were determined and their evolution with Φ is highlighted. Mechanical characterization of the deposited coatings was performed, where the hardness tests showed that on average the HiPIMS coatings (29-34GPa) were some 5 GPa harder than dcMS coatings (25-27GPa).