Phosphate Coatings Enriched with Copper on Titanium Substrate Fabricated Via DC-PEO Process

Area of Science:

• Materials Science
• Surface Engineering
• Electrochemistry

Background:

• Titanium substrates are widely used in biomedical and industrial applications.
• Developing advanced porous coatings with specific functionalities, like copper enrichment, is crucial for enhancing material performance.
• Direct Current Plasma Electrolytic Oxidation (DC-PEO) offers a versatile method for surface modification.

Purpose of the Study:

• To investigate the fabrication of advanced porous coatings enriched in copper on a titanium substrate.
• To explore the influence of electrolyte composition and voltage on coating properties.
• To characterize the structure, composition, and porosity of the obtained coatings.

Main Methods:

• Direct Current Plasma Electrolytic Oxidation (DC-PEO) with voltage control.
• Electrolytes based on concentrated orthophosphoric acid with copper(II) nitrate(V) trihydrate.
• Characterization techniques including X-Ray Photoelectron Spectroscopy (XPS), X-Ray Diffraction (XRD), and Energy-Dispersive X-Ray Spectroscopy (EDS), Glow-Discharge Optical Emission Spectroscopy (GDOES).

Main Results:

• Variable porosity coatings were fabricated, quantifiable by the 3D parameter Sz (9.72–45.18 μm).
• Copper in both Cu⁺ and Cu²⁺ oxidation states was incorporated into the coatings (0.24–2.59 at%).
• The Cu/P ratio increased with higher voltage and salt concentration, and a three-layer structure was identified.

Conclusions:

• DC-PEO is effective for creating copper-enriched porous coatings on titanium.
• Electrolyte composition and voltage significantly influence coating porosity, copper content, and structure.
• The fabricated coatings exhibit a multi-layered structure with potential for tailored applications.