scholarly journals XPS and GDOES Characterization of Porous Coating Enriched with Copper and Calcium Obtained on Tantalum via Plasma Electrolytic Oxidation

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Krzysztof Rokosz ◽  
Tadeusz Hryniewicz ◽  
Patrick Chapon ◽  
Steinar Raaen ◽  
Hugo Ricardo Zschommler Sandim

XPS and GDOES characterizations of porous coatings on tantalum after Plasma Electrolytic Oxidation (PEO) at 450 V for 3 minutes in electrolyte containing concentrated (85%) phosphoric acid with calcium nitrate and copper (II) nitrate are described. Based on the obtained data, it may be concluded that the PEO coating consists of tantalum (Ta5+), calcium (Ca2+), copper (Cu2+  and Cu+), and phosphates (PO43-). It has to be pointed out that copper and calcium are distributed throughout the volume. The authors also propose a new model of PEO, based on the derivative of GDOES signals with sputtering time.

2017 ◽  
Vol 17 (2) ◽  
pp. 41-54 ◽  
Author(s):  
K. Rokosz ◽  
T. Hryniewicz ◽  
K. Pietrzak ◽  
W. Malorny

AbstractThe SEM and EDS results of porous coatings formed on pure titanium by Plasma Electrolytic Oxidation (Micro Arc Oxidation) under DC regime of voltage in the electrolytes containing of 500 g zinc nitrate Zn(NO3)2·6H2O in 1000 mL of concentrated phosphoric acid H3PO4at three voltages, i.e. 450 V, 550 V, 650 V for 3 minutes, are presented. The PEO coatings with pores, which have different shapes and the diameters, consist mainly of phosphorus, titanium and zinc. The maximum of zinc-to-phosphorus (Zn/P) ratio was found for treatment at 650 V and it equals 0.43 (wt%) | 0.20 (at%), while the minimum of that coefficient was recorded for the voltage of 450 V and equaling 0.26 (wt%) | 0.12 (at%). Performed studies have shown a possible way to form the porous coatings enriched with zinc by Plasma Electrolytic Oxidation in electrolyte containing concentrated phosphoric acid H3PO4with zinc nitrate Zn(NO3)2·6H2O.


Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1680 ◽  
Author(s):  
Krzysztof Rokosz ◽  
Tadeusz Hryniewicz ◽  
Sofia Gaiaschi ◽  
Patrick Chapon ◽  
Steinar Raaen ◽  
...  

In this paper, the characteristics of new porous coatings fabricated at three voltages in electrolytes based on H3PO4 with calcium nitrate tetrahydrate, magnesium nitrate hexahydrate, and copper(II) nitrate trihydrate are presented. The SEM, energy dispersive spectroscopy (EDS), glow discharge optical emission spectroscopy (GDOES), X-ray photoelectron spectroscopy (XPS), and XRD techniques for coating identification were used. It was found that the higher the plasma electrolytic oxidation (PEO) (micro arc oxidation (MAO)) voltage, the thicker the porous coating with higher amounts of built-in elements coming from the electrolyte and more amorphous phase with signals from crystalline Ca(H2PO4)2∙H2O and/or Ti(HPO4)2∙H2O. Additionally, the external parts of the obtained porous coatings formed on titanium consisted mainly of Ti4+, Ca2+, Mg2+ and PO43−, HPO42−, H2PO4−, P2O74− as well as Zn2+ or copper Cu+/Cu2+. The surface should be characterized by high biocompatibility, due to the presence of structures based on calcium and phosphates, and have bactericidal properties, due to the presence of zinc and copper ions. Furthermore, the addition of magnesium ions should accelerate the healing of postoperative wounds, which could lead to faster patient recovery.


Author(s):  
Krzysztof Rokosz ◽  
Tadeusz Hryniewicz ◽  
Antje Schütz ◽  
Jan Heeg ◽  
Marion Wienecke ◽  
...  

2016 ◽  
Vol 16 (1) ◽  
pp. 5-16 ◽  
Author(s):  
K. Rokosz ◽  
T. Hryniewicz ◽  
W. Malorny

Abstract The SEM and EDS results of coatings obtained on pure niobium and titanium alloys (NiTi and Ti6Al4V) by Plasma Electrolytic Oxidation in the electrolytes containing of 300 g and 600 g copper nitrate in 1 litre of concentrated phosphoric acid at 450 V for 3 minutes, are presented. The obtained coatings are porous and consist mainly of phosphorus within titanium and copper. For each coating, the Cu/P ratios were calculated. The maximum of that coefficient was found for niobium and Ti6Al4V alloy oxidised in the electrolyte containing 600 g of Cu(NO3)2 in 1 dm3 of H3PO4 and equaling to 0.22 (wt%) | 0.11 (at%). The minimum of Cu/P ratio was recorded for NiTi and Ti6Al4V alloys oxidised by PEO in electrolyte consisting of 300 g of copper nitrate in 1 dm3 of concentrated phosphoric acid and equals to 0.12 (wt%) | 0.06 (at%). The middle value of that ratio was recorded for NiTi and it equals to 0.16 (wt%) | 0.08 (at%).


2017 ◽  
Vol 17 (4) ◽  
pp. 55-67 ◽  
Author(s):  
K. Rokosz ◽  
T. Hryniewicz ◽  
K. Pietrzak ◽  
P. Sadlak ◽  
J. Valíček

Abstract The purpose of this work is to produce and characterize (chemical composition and roughness parameters) porous coatings enriched in calcium and phosphorus on the titanium (CP Titanium Grade 2) by plasma electrolytic oxidation. As an electrolyte, a mixture of phosphoric acid H3PO4 and calcium nitrate Ca(NO3)2·4H2O was used. Based on obtained EDS and roughness results of PEO coatings, the effect of PEO voltages on the chemical composition and surface roughness of porous coatings was determined. With voltage increasing from 450 V to 650 V, the calcium in PEO coatings obtained in freshly prepared electrolyte was also found to increase. In addition, the Ca/P ratio increased linearly with voltage increasing according to the formula Ca/P = 0.035·U+0.176 (by wt%) and Ca/P = 0.03·U+0.13 (by at%). It was also noticed that the surface roughness increases with the voltage increasing, what is related to the change in coating porosity, i.e. the higher is the surface roughness, the bigger are pores sizes obtained.


2016 ◽  
Vol 862 ◽  
pp. 86-95 ◽  
Author(s):  
Krzysztof Rokosz ◽  
Tadeusz Hryniewicz ◽  
Winfried Malorny

The main goal of present paper is to obtain porous coatings enriched in copper by Plasma Electrolytic Oxidation on titanium and niobium as well as on NiTi and Ti6Al4V alloys. Performed SEM and EDS studies confirmed the hypothesis that it is possible to create the porous surfaces with pores, which shapes and size are different. In order to show the copper enrichment inside the surface layers, the copper-to-phosphorus ratios were used. Based on these ratios it may be concluded that average value of Cu/P is maximal for NiTi alloy after oxidation in electrolyte containing 300 g of copper nitrate in 1 liter of phosphoric acid and equals 0.26. The minimum of Cu/P ratio equaling to 0.12 was recorded for pure titanium and pure niobium treated in electrolyte containing 300 g of Cu (NO3)2 in 1 L H3PO4.


2016 ◽  
Vol 16 (3) ◽  
pp. 15-25 ◽  
Author(s):  
K. Rokosz ◽  
T. Hryniewicz ◽  
Ł. Dudek ◽  
A. Schütz ◽  
J. Heeg ◽  
...  

Abstract The SEM and EDS study results of coatings obtained on titanium by Plasma Electrolytic Oxidation (PEO) in the electrolytes containing of 600 g copper nitrate in 1 liter of concentrated phosphoric acid at 450 V for 1 and 3 minutes, are presented. The obtained coatings are porous and consist mainly of phosphorus within titanium and copper. It was found that the time of PEO oxidation has impact on the chemical composition of the coatings. The longer time of PEO treatment, the higher amount of copper inside coating. The PEO oxidation of titanium for 1 minute has resulted in the creation of coating, on which 3 phases where found, which contained up to 13.4 wt% (9 at%) of copper inside the phosphate structure. In case of 1 minute PEO treatment of titanium, the 2 phases were found, which contained up to 13 wt% (8 at%) of copper inside the phosphate structure. The copper-to-phosphorus ratios after 1 minute processing belong to the range from 0.28 by wt% (0.14 by at%) to 0.47 by wt% (0.23 by at%), while after 3 minutes the same ratios belong to the range from 0.27 by wt% (0.13 by at%) to 0.35 by wt% (0.17 by at%). In summary, it should be stated that the higher amounts of phosphorus and copper were recorded on titanium after PEO oxidation for 3 minutes than these after 1 minute.


ACS Omega ◽  
2020 ◽  
Vol 5 (38) ◽  
pp. 24186-24194
Author(s):  
Marzieh Mardali ◽  
Hamidreza Salimijazi ◽  
Fathallah Karimzadeh ◽  
Carsten Blawert ◽  
Bérengère J. C. Luthringer-Feyerabend ◽  
...  

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 116 ◽  
Author(s):  
Bernd Engelkamp ◽  
Björn Fischer ◽  
Klaus Schierbaum

Oxide layers on titanium foils were produced by galvanostatically controlled plasma electrolytic oxidation in 12.9 M sulfuric acid with small amounts of phosphoric acid added up to a 3% mole fraction. In pure sulfuric acid, the oxide layer is distinctly modified by plasma discharges. As the time of the process increases, rough surfaces with typical circular pores evolve. The predominant crystal phase of the titanium dioxide material is rutile. With the addition of phosphoric acid, discharge effects become less pronounced, and the predominant crystal phase changes to anatase. Furthermore, the oxide layer thickness and mass gain both increase. Already small amounts of phosphoric acid induce these effects. Our findings suggest that anions of phosphoric acid preferentially adsorb to the anodic area and suppress plasma discharges, and conventional anodization is promoted. The process was systematically investigated at different stages, and voltage and oxide formation efficiency were determined. Oxide surfaces and their cross-sections were studied by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The phase composition was determined by X-ray diffraction and confocal Raman microscopy.


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