The effect of N+ ion-implantation on the corrosion resistance of HiPIMS-TiN coatings sealed by ALD-layers.

Plasma immersion ion implantation (PIII) was studied as a pretreatment method for improving the surface activity of TiN coatings deposited by high power impulse magnetron sputtering (HiPIMS) before being sealed with an ALD (Atomic layer deposition)-Al 2 O 3 hybrid coating. The effect of different implantation energy and dose of nitrogen plasma on the microstructure and surface morphology of TiN coatings were investigated, and the surface morphology and fracture cross-section images of TiN/Al 2 O 3 hybrid coatings with and without PIII pretreatment were compared. The corrosion protection properties were explored with linear sweep voltammetry in 3.5% NaCl solution at the room temperature. The results indicated that the N+ pre-ion-implantation had a significant influence on the microstructure and surface morphology of TiN coatings. With the increase of ion implantation energy and dose, TiN coatings gradually alter from the preferred orientation (200) to a mixture of (200) and (111), accompanied by the decrease of grain size on the surface. Moreover, the PIII pretreatment of the TiN coatings could significantly shorten the incubation time of the nucleation of ALD films, leading to a denser but thinner (at the same deposition cycles) layer of Al 2 O 3 , which plays a positive role in corrosion resistance. The coverage of ALD-Al 2 O 3 films was improved with the increase of the nitrogen ion implantation energy and dose, resulting in better corrosion protection. • The TiN/Al 2 O 3 hybrid coatings were designed and deposited by combining HiPIMS, PIII, and ALD. • The N+ ion-implantation has significant influences on the microstructure and surface morphology of TiN coatings. • The PIII pretreat the TiN coatings cloud significantly shorten the incubation time of the nucleation of ALD films. • The corrosion performance of hybrid coatings was improved with the increase of the N+ ion implantation energy and dose. [ABSTRACT FROM AUTHOR]