The Effect of PEO Treatment in a Ta-Rich Electrolyte on the Surface and Corrosion Properties of Low-Carbon Steel for Potential Use as a Biomedical Material

Abstract

Fe-based materials have extensive applications in the building and automobile industries due to their excellent mechanical properties and low cost. However, their biomedical employment is restricted by the corrosion propensity when in contact with bodily fluids. In this study, single-step Plasma Electrolytic Oxidation, PEO, treatment in Ta-rich electrolyte was used, for the first time, to improve the corrosion resistance of low-carbon steel SAE 1020 for possible use as device implants. The effect of the applied voltage on the chemical and phase composition, topography, wettability, roughness, and corrosion properties were addressed. The results indicated that the Fe-based oxide coatings had a rough and hydrophilic surface, increasing the Ta content with the applied potential. The phase composition of the coatings was mainly composed of hematite (Fe2O3), with the Fourier-transform Infrared Spectroscopy, FTIR, spectrums indicating the presence of some absorbed water and organic molecules. The corrosion resistance of the PEO-treated samples was better than the substrate against saline solution (0.9% NaCl) due to the Fe2O3 growth decorated with Ta particles, especially the sample treated at 200 V. The results state that Ta-enriched Fe-based oxide coatings could significantly improve the applicability of low-carbon steel SAE 1020 as a low-cost biomaterial, particularly for medical devices.

Alloying Element Depletion and Phase Transition in Stainless Steel 304 Induced by PEO Treatment in KOH- and TaOH-Rich Electrolyte

“…Similar results were obtained for the other samples of each PEO treatment condition (see Figures S1-S5 in Supplementary Material). Marcuz et al [20] found similar curves during PEO treatment on low-carbon steel, which was related to the oxidative reaction and plasma discharges that occurred on the surface.…”

“…The open-circuit potential (OCP) was previously measured for 1 h. Then, the potentiodynamic polarization (PDP) test was performed from −1 to 2 V vs. OCP, with a scan rate of 1 mV•s −1 and step size of 1 mV. The obtained results were analyzed using NOVA 2.0 ® software (version 2.1.5), which evaluated the corrosion potential (E corr ), corrosion current density (i corr ), and polarization resistance (R p ) using Tafel's extrapolation method and the Butler-Volmer equation [20]. Finally, the electrochemical impedance spectroscopy (EIS) test was performed in the frequency range of 100 kHz to 100 mHz with ten points per decade and a signal amplitude of V rms = 10 mV.…”

“…The authors obtained superior corrosion properties compared to the bare material, which could positively impact its applications. And finally, Marcuz et al [20] applied the PEO technique under a Ta-rich electrolyte on the low-carbon steel Q235 at distinct voltages. They obtained a significant improvement in corrosion resistance against 0.9% NaCl solution, which mimics the physiological environment of the human body.…”

Effects of Process Parameters on Microstructure and Wear Resistance of Laser Cladding A-100 Ultra-High-Strength Steel Coatings

“…Metal materials are the most widely used materials in industrial and agricultural production. Among many metal materials, mild steel is widely used in automobile, ship and machinery manufacturing because of its advantages of good formability, excellent plasticity and higher cost performance [1][2][3]. However, mild steel also has some inherent weaknesses, such as low hardness and poor wear resistance, which cause a reduction in the suitable life of mild steel [4].…”

Possibilities of Duplex Plasma Electrolytic Treatment for Increasing the Hardness and Wear Resistance of a Commercially Pure Titanium Surface

“…An alternative method of modifying metal and alloy surfaces to increase a variety of performance indicators is plasma electrolytic treatment [4][5][6][7]. There are a variety of processes aimed at obtaining ceramic-like coatings by plasma electrolytic oxidation [8][9][10][11][12][13][14] and surface polishing or removal of the surface layer by plasma electrolytic polishing (PEP) [15][16][17][18][19][20][21][22].…”