Influence of Electrolyte Composition and Voltage on the Microstructure and Growth Mechanism of Plasma Electrolytic Oxidation (PEO) Coatings on Tantalum: A Review

Fattah-alhosseini, Arash; Molaei, Maryam; Babaei, Kazem

Influence of Electrolyte Composition and Voltage on the Microstructure and Growth Mechanism of Plasma Electrolytic Oxidation (PEO) Coatings on Tantalum: A Review

Authors

Arash Fattah-alhosseini

Maryam Molaei

Kazem Babaei

Department of Materials Engineering, Bu-Ali Sina University, Hamedan 65178-38695, Iran

Abstract

Recently, PEO process of tantalum has been developed as a method of producing corrosion-resistant, hard, wear-resistant, and biocompatible as well as having good adhesion coatings. In this review, we present the results of PEO process of tantalum in three main electrolytes. This review tries to measure the effect of electrolyte composition and voltage that were used within PEO procedure on the surface behavior of the produced oxide coatings on Ta. The results of the PEO treatment of Ta in H₄SiW₁₂O₄₀ electrolyte revealed that the morphology of oxide coatings really depends on the PEO procedure time. Density of discharge channels declines as their diameter rises. This leads to an increase in the oxide coating roughness within the PEO procedure of tantalum. In electrolytes of β-glycerophosphate disodium and calcium acetate, the results indicated that the employed voltage significantly affected morphologies, the coatings bond strength and the phase components. However, it affected surface chemical species a little. Finally, in 0.5 M Ca (H₂PO₂)₂ electrolytes, the results revealed that using a precise control on the procedure voltage, tuning the obtained coatings thickness is possible in addition to their roughness, adhesion strength and relative values of the electrolyte type inside the modified surfaces of tantalum.

Keywords

Plasma electrolytic oxidation (PEO)

Tantalum

Calcium phosphate

12-tungstosilicic acid

β-glycerophosphate disodium