scholarly journals Self-Lubricating PEO–PTFE Composite Coating on Titanium

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 170 ◽  
Author(s):  
Limei Ren ◽  
Tengchao Wang ◽  
Zhaoxiang Chen ◽  
Yunyu Li ◽  
Lihe Qian
Keyword(s):  
Composite Coating ◽  
Tribological Properties ◽  
Plasma Electrolytic Oxidation ◽  
Composite Coatings ◽  
Pure Titanium ◽  
Tio2 Coating ◽  
Commercially Pure Titanium ◽  
Ptfe Composite ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

A self-lubricating plasma electrolytic oxidation–polytetrafluoroethylene (PEO–PTFE) composite coating was successfully fabricated on the surface of commercially pure titanium by a multiple-step method of plasma electrolytic oxidation, dipping and sintering treatment. The microstructure and tribological properties of the PEO–PTFE composite coating were investigated and compared with the PEO TiO2 coating and the PTFE coating on titanium. Results show that most of the micro-pores of the PEO TiO2 coating were filled by PTFE and the surface roughness of PEO–PTFE composite coating was lower than that of the PEO TiO2 coating. Furthermore, the PEO–PTFE composite coating shows excellent tribological properties with low friction coefficient and low wear rate. This study provides an insight for guiding the design of self-lubricating and wear-resistant PEO composite coatings.

scholarly journals Comparison of Biocompatible Coatings Produced by Plasma Electrolytic Oxidation on cp-Ti and Ti-Zr-Nb Superelastic Alloy

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 401
Author(s):  
Ruzil Farrakhov ◽  
Olga Melnichuk ◽  
Evgeny Parfenov ◽  
Veta Mukaeva ◽  
Arseniy Raab ◽  
...  
Keyword(s):  
Plasma Electrolytic Oxidation ◽  
Electrochemical Impedance ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
X Ray ◽  
Kinetic Coefficients ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Cp Ti ◽  
Peo Coatings

The paper compares the coatings produced by plasma electrolytic oxidation (PEO) on commercially pure titanium and a novel superelastic alloy Ti-18Zr-15Nb (at. %) for implant applications. The PEO coatings were produced on both alloys in the identical pulsed bipolar regime. The properties of the coatings were examined using scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS). The PEO process kinetics was modeled based on the Avrami theorem and Cottrell equation using a relaxation method. The resultant coatings contain TiO2, for both alloys, and NbO2, Nb2O5, ZrO2 for Ti-18Zr-15Nb alloy. The coating on the Ti-18Zr-15Nb alloy has a higher thickness, porosity, and roughness compared to that on cp-Ti. The values of the kinetic coefficients of the PEO process—higher diffusion coefficient and lower time constant for the processing of Ti-18Zr-15Nb—explain this effect. According to the electrochemical studies, PEO coatings on Ti-18Zr-15Nb alloy provide better corrosion protection. Higher corrosion resistance, porosity, and roughness contribute to better biocompatibility of the PEO coating on Ti-18Zr-15Nb alloy compared to cp-Ti.

scholarly journals Improvement of Mechanical and Corrosion Properties of Commercially Pure Titanium Using Alumina PEO Coatings

Coatings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 29
Author(s):  
Viorel Malinovschi ◽  
Alexandru Horia Marin ◽  
Catalin Ducu ◽  
Sorin Moga ◽  
Victor Andrei ◽  
...  
Keyword(s):  
Plasma Electrolytic Oxidation ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Corrosion Properties ◽  
Commercially Pure ◽  
Electrolytic Oxidation ◽  
Aluminum Oxide Layer ◽  
Plasma Electrolytic ◽  
Cp Ti ◽  
Peo Coatings

In this study, the surface of commercially pure titanium (Cp-Ti) was covered by a 21–95 µm-thick aluminum oxide layer using plasma electrolytic oxidation. Coating characterization revealed the formation of nodular and granular α- and γ-Al2O3 phases with minor amounts of TiAl2O5 and Na2Ti4O9 which yielded a maximum 49.0 GPa hardness and 50 N adhesive critical load. The corrosion resistance behavior in 3.5 wt.% NaCl solution of all plasma electrolytic oxidation (PEO) coatings was found to be two orders of magnitude higher compared to bare Ti substrate.

scholarly journals Microstructure and Tribological Properties of Micro-arc Oxidation TiO2 Coating Before and After SiC Particles Incorporation

2019 ◽  
Vol 25 (3) ◽  
pp. 270-275
Author(s):  
Limei REN ◽  
Tengchao WANG ◽  
Zhaoxiang CHEN ◽  
Xipeng REN ◽  
Xiaowen QI
Keyword(s):  
Composite Coating ◽  
Tribological Properties ◽  
Pure Titanium ◽  
Tio2 Coating ◽  
Commercially Pure Titanium ◽  
Sic Particles ◽  
Micro Cracks ◽  
Before And After ◽  
Micro Arc Oxidation ◽  
Steel Balls

In this work, porous TiO2 coating was fabricated on the surface of commercially pure titanium using the micro-arc oxidation (MAO) technique, and the effect of SiC particles incorporation on the microstructure and tribological properties of MAO TiO2 coating was investigated. Results show that submicron SiC particles dispersed in the MAO electrolyte were incorporated into the TiO2 coating during the MAO process and the fabricated TiO2/SiC composite coating mainly consisted of rutile, anatase and SiC phases. The pore size and surface roughness of TiO2/SiC composite coating decreased with the increasing addition amount of SiC particles in the electrolyte. Furthermore, the incorporation of SiC particles in the TiO2 coating suppressed the initiation and propagation of micro-cracks. The tribological test of coatings against GCr15 stainless steel balls show that the incorporation of submicron SiC particles in the MAO TiO2 coating decreased the friction coefficient and wear rate. DOI: http://dx.doi.org/10.5755/j01.ms.25.3.20089

scholarly journals Atmospheric and Marine Corrosion of PEO and Composite Coatings Obtained on Al-Cu-Mg Aluminum Alloy

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2739 ◽  
Author(s):  
Vladimir S. Egorkin ◽  
Ivan M. Medvedev ◽  
Sergey L. Sinebryukhov ◽  
Igor E. Vyaliy ◽  
Andrey S. Gnedenkov ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Composite Coating ◽  
Corrosion Protection ◽  
Plasma Electrolytic Oxidation ◽  
Composite Coatings ◽  
Marine Corrosion ◽  
X Ray ◽  
Electrolytic Oxidation ◽  
Natural Oxide ◽  
Plasma Electrolytic

Wrought Al-Cu-Mg aluminum alloy (D16) was treated by bipolar plasma electrolytic oxidation to create a base plasma electrolytic oxidation (PEO)-coating with corrosion protection and mechanical properties superior to bare alloy’s natural oxide layer. Additional protection was provided by the application of polymer, thus creating a composite coating. Electrochemical and scratch tests, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction studies were performed. Degradation of coatings in the marine atmosphere and seawater was evaluated. The composite polymer-containing coating provided better corrosion protection of aluminum alloy compared to the PEO-coating, although seawater affected both. During the atmospheric exposure, the PEO-coating provided reasonably good protection, and the composite coating showed excellent performance.

Preparation and Tribological Properties of Graphite-Containing Plasma Electrolytic Oxidation Coatings on Al Alloy

2014 ◽  
Vol 1081 ◽  
pp. 183-186
Author(s):  
Qing Biao Li ◽  
Qing Wang ◽  
Jun Liang
Keyword(s):  
Tribological Properties ◽  
Plasma Electrolytic Oxidation ◽  
Composite Coatings ◽  
Al Alloy ◽  
Constant Voltage ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

Graphite-containing plasma electrolytic oxidation (PEO) composite coatings were prepared on Al alloy using periodically constant voltage, with addition of graphite in silicate electrolyte. The surface and cross-sectional morphologies of the coatings were examined using scanning electron microscope (SEM), the composition of the coatings was investigated by X-ray diffraction (XRD) and Raman spectra, the tribological properties of the coatings were evaluated on a tribometer. The results show that friction-reducing PEO composite coatings on Al alloy can be prepared in graphite-dispersed electrolyte using periodically constant voltage, the yielded coatings exhibit relatively lower and more stable friction coefficient.

scholarly journals Bioactive Coatings Formed on Titanium by Plasma Electrolytic Oxidation: Composition and Properties

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4121 ◽  
Author(s):  
Dmitry V. Mashtalyar ◽  
Konstantine V. Nadaraia ◽  
Andrey S. Gnedenkov ◽  
Igor M. Imshinetskiy ◽  
Mariia A. Piatkova ◽  
...  
Keyword(s):  
Plasma Electrolytic Oxidation ◽  
Electrochemical Impedance ◽  
Pure Titanium ◽  
Corrosion Current ◽  
Bare Metal ◽  
Commercially Pure Titanium ◽  
Bioactive Coatings ◽  
Commercially Pure ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

Bioactive coatings on VT1-0 commercially pure titanium were formed by the plasma electrolytic oxidation (PEO). A study of the morphological features of coatings was carried out using scanning electron microscopy. A composition of formed coatings was investigated using energy-dispersive spectroscopy and X-ray diffractometry analysis. It was shown that PEO-coatings have calcium phosphate in their composition, which increases the bioactivity of the surface layer. Electrochemical properties of the samples were studied by potentiondynamic polarization and electrochemical impedance spectroscopy in different physiological media: simulated body fluid and minimum essential medium. The data of electrochemical studies indicate more than 15 times decrease in the corrosion current density for the sample with coating (5.0 × 10−9 A/cm2) as compared to the bare titanium (7.7 × 10−8 A/cm2). The formed PEO-layers have elastoplastic properties close to human bone (12–30 GPa) and a lower friction coefficient in comparison with bare metal. The wettability of PEO-layers increased. The contact angle for formed coatings reduced by more than 60° in comparison with bare metal (from 73° for titanium to 8° for PEO-coating). Such an increase in surface hydrophilicity contributes to the greater biocompatibility of the formed coating in comparison with commercially pure titanium. PEO can be prospective as a method for improving titanium surface bioactivity.

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