Protective nature of nano-TiN coatings shaped by EPD on Ti substrates

Abstract

A B S T R A C TThe hardness and corrosion resistance of TiN coatings, processed by Electrophoretic Deposition (EPD) to cover polished and unpolished Ti substrates, have been evaluated. A deposition time of 5 min has been enough to obtain a cohesive layer of 7-8 μm in thickness. The coatings were thermally treated in vacuum atmosphere at 1200°C for 1 h with heating and cooling rates of 5°C min The nanohardness values of the polished samples have been increased from 2.8-4.8 GPa up to 6.5-8.5 GPa. Besides, the corrosion current density has been reduced more than one order of magnitude obtaining a protective efficiency of 82%. These values have been compared with other works in literature where authors used complex and costly processing techniques, demonstrating the strong impact of the colloidal processing over the specific properties of the material.

Thin TiN coating on NiTi substrate through PVD method: Improvement of the wear resistance

“…Other studies reported that the thickness of TiN coating can be 1-5 µm [43]. The normal thickness of the TiN coating is also reported to be about 3-4 µm [36], and also 7-8 µm [26]. Generally, a thickness of about 1 µm for the PVD coatings, which was achieved in this study, is considered as a thin coating.…”

“…TiN coating of 1.7 μm has been deposited on Ti and Ti alloy through magnetron sputtering; they observed an enhancement in mechanical properties (good resistance to scratch and hardness) [15]. The corrosion resistance and hardness of TiN coatings (7-8 μm in thickness) applied by electrophoretic deposition on Ti substrates have been evaluated by Mendoza et al [26]. It has been reported [27] that TiCN-coated NiTi parts by magnetron sputtering are capable of presenting remarkable tribological performance.…”

Surface Optimization of Commercial Porous Ti Substrates by EPD of Titanium Nitride

“…For example, Cui et al, describe the preparation of homogeneous and adhesive nanocrystalline TiN thin films from aqueous suspensions of TiN nanometric powders, obtaining 6 µm thick coatings after 10 min of deposition time by applying 10 V of deposition voltage [ 58 ]. More recently, Ureña [ 59 ] and Mendoza [ 60 ] prepared TiN protective coatings on Ti substrates to improve their wear resistance and to reduce the surface Young’s modulus for biomedical applications. Homogeneous coatings were obtained after 5 min by applying 90 V of deposition voltage.…”

“…Most of the papers in the literature report the study of suspensions of TiN powders in organic solvents. Mendoza et al [ 57 , 60 ] and Ureña et al [ 59 ] prepared TiN nanopowder suspensions using isopropyl alcohol as solvent and polyethilenimine (PEI) as stabilizer. Isopropanol was also used as media for the preparation of TiN-based suspensions on stainless steel substrates by EPD [ 53 , 55 ].…”

Corrosion and tribocorrosion behaviour of titanium nitride thin films grown on titanium under different deposition times

“…Furthermore, in the literature, most of TiN coatings have been performed at high deposition temperatures (500-1100°C) [6,22,28,31,[33][34][35][36][37][38], which may cause mechanical, microstructural and chemical damage to the substrate [39][40][41]. Therefore, sputtering is a promising route due to easy control of deposition rate, high ionization rate, creation of high-density plasma, and preferable energy of deposition material improving the adhesion of coating layer [42].…”