Addition of Organic Acids during PEO of Titanium in Alkaline Solution

This research study describes recent advances in understanding the effects of addition organic acids, such as acetic, lactic, citric and phytic on process plasma electrolytic oxidation (PEO) Ti using an alkaline bath. As developed over workpiece is central to determine particular morphological structural features growing oxide, focus then inter-relationships between electrolyte resultant regime established. In situ optical emission spectroscopy (OES) allowed us verify a marked suppression when adding low-molecular-weight anions acetates, resulting short-lived well-distributed discharges. Conversely, more bulky anions, lactates, citrates phytates, were considered, less efficient shielding electrode caused build-up long-lasting destructive sparks responsible for formation thicker coatings, even >30 µm, at expense higher roughness loss compactness. Corrosion resistance was tested electrochemically, according electrochemical impedance (EIS), weight losses evidenced coatings produced solution containing acetates be suitable service H2SO4.