Modification of Ti-Al-V Alloys with Layers Containing TiN Particles Obtained via the Electrophoretic Deposition Process: Surface and Structural Properties

The aim of this work was to obtain homogenous coatings containing chitosan with different concentrations of titanium nitride particles (TiN). The coatings were deposited via an electrophoretic process on an etched medically pure Ti-6Al-4V alloy. As part of the study, the zeta potential of the suspensions used for EPD coating deposition was measured, allowing for the optimization of process parameters and the assessment of suspension stability. Subsequently, the research focused on evaluating the microstructure (SEM + EDS), structure (XRD), and surface characteristics (roughness, contact angle, surface energy, microhardness, coating adhesion) of the deposited layers. SEM microscopy confirmed the effective deposition of titanium nitride particles onto the titanium alloy surface. XRD analysis proved the assumed phase composition of the coating. The increase in TiN phase content in the individual layers was confirmed. The chitosan/TiN layer's introduction altered the alloy surface, increasing its roughness and static water contact angle. The highest roughness and hydrophobic properties were observed in the coating with a 2 wt.% concentration of titanium nitride particles. Additionally, the coating containing the highest concentration of ceramic particles (2 wt.%) exhibited the highest hardness (197 HV) among all the tested layers. However, the TiN particles incorporation in the layer decreased the adhesion strength, from 2.36 MPa (0.5 wt.% TiN) to 1.04 MPa (2 wt.% TiN). The coatings surface and structural properties demonstrate potential as protective layers for implants and are suitable for further biological studies to assess their applicability in medical and veterinary fields.