Microstructure and Properties of Nanostructured Calcium Phosphate/Titania Porous Coatings via Micro Arc Oxidation

Author(s):  
Sakine Abbasi ◽  
Hamid Reza Rezaie ◽  
Farhad Golestani-Fard
2018 ◽  
Vol 212 ◽  
pp. 37-40 ◽  
Author(s):  
Jinhe Dou ◽  
Chunyan Wang ◽  
Guochao Gu ◽  
Chuanzhong Chen

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3693
Author(s):  
Yurii P. Sharkeev ◽  
Ekaterina G. Komarova ◽  
Valentina V. Chebodaeva ◽  
Mariya B. Sedelnikova ◽  
Aleksandr M. Zakharenko ◽  
...  

A modern trend in traumatology, orthopedics, and implantology is the development of materials and coatings with an amorphous–crystalline structure that exhibits excellent biocopatibility. The structure and physico–chemical and biological properties of calcium phosphate (CaP) coatings deposited on Ti plates using the micro-arc oxidation (MAO) method under different voltages (200, 250, and 300 V) were studied. Amorphous, nanocrystalline, and microcrystalline statesof CaHPO4 and β-Ca2P2O7were observed in the coatings using TEM and XRD. The increase in MAO voltage resulted in augmentation of the surface roughness Ra from 2.5 to 6.5 µm, mass from 10 to 25 mg, thickness from 50 to 105 µm, and Ca/P ratio from 0.3 to 0.6. The electrical potential (EP) of the CaP coatings changed from −456 to −535 mV, while the zeta potential (ZP) decreased from −53 to −40 mV following an increase in the values of the MAO voltage. Numerous correlations of physical and chemical indices of CaP coatings were estimated. A decrease in the ZP magnitudes of CaP coatings deposited at 200–250 V was strongly associated with elevated hTERT expression in tumor-derived Jurkat T cells preliminarily activated with anti-CD2/CD3/CD28 antibodies and then contacted in vitro with CaP-coated samples for 14 days. In turn, in vitro survival of CD4+ subsets was enhanced, with proinflammatory cytokine secretion of activated Jurkat T cells. Thus, the applied MAO voltage allowed the regulation of the physicochemical properties of amorphous–crystalline CaP-coatings on Ti substrates to a certain extent. This method may be used as a technological mechanism to trigger the behavior of cells through contact with micro-arc CaP coatings. The possible role of negative ZP and Ca2+ as effectors of the biological effects of amorphous–crystalline CaP coatings is discussed. Micro-arc CaP coatings should be carefully tested to determine their suitability for use in patients with chronic lymphoid malignancies.


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.


2008 ◽  
Vol 368-372 ◽  
pp. 1194-1197 ◽  
Author(s):  
Chen Ma ◽  
Ying Hui Wang ◽  
Mu Qin Li ◽  
Li Jie Qu

Rare earth/calcium phosphate composite coatings were fabricated on the surface of Ti-6Al-4V by micro-arc oxidation (MAO) technique. The wear properties and corrosion resistant of rare earth/ calcium phosphate composite coatings in the simulated body fluid (SBF) have been investigated and the bioactivity of the composite coatings were evaluated. The results show that the friction coefficient of the composite coatings in the SBF is only 0.15~0.18 and the anode polarization potential of the coating has been obviously enhanced about 0.18V compared with that of coatings of calcium phosphate coatings. So the composite coatings have excellent wear and corrosion resistant properties. XRD analysis indicates that the composite coatings can induce hydroxyapatite to form on its surface after soaked in SBF for 9d, which shows that the composite coatings own good bioactivity.


2015 ◽  
Vol 36 (4) ◽  
pp. 1178-1182 ◽  
Author(s):  
Min Wang ◽  
Guoge Zhang ◽  
Wenfang Li ◽  
Xiaojun Wang

2010 ◽  
Vol 434-435 ◽  
pp. 586-589
Author(s):  
Min Zheng ◽  
Ding Fan ◽  
Jian Bin Zhang ◽  
Xiu Kun Li

The calcium phosphate bioceramic coating was fabricated on titanium alloy (Ti-6Al-4V) substrate by a 5kW continuous transverse flow CO2 laser. Due to the peculiar role of rare earth oxide in laser cladding, the effect of ceria additive on the microstructure and properties of laser-cladded bioceramic coating was investigated by means of scanning electron microscope (SEM), X-ray diffraction (XRD), microhardness and corrosion resistance testing. The results indicate that the appearance of rare earth oxide ceria in the precursor powders has an impact on the microstructure and properties of the laser-cladded bioceramic coating. Calcium phosphate bioceramic such as hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) are synthesized on the top surface of laser-cladded specimens. And the addition of rare earth oxide ceria in pre-placed powders has an influence on the formation of calcium phosphate bioceramic phases. Furthermore, it reveals that the laser-cladded bioceramic coating of ceria additive in pre-placed powders has more favorable microhardness and corrosion resistance compared with the coating without rare earth oxide.


2007 ◽  
Vol 330-332 ◽  
pp. 629-632 ◽  
Author(s):  
Kai Hui Nan ◽  
G.X. Pei

Titanium oxide films were obtained by MAO at the applied voltages of 250-550V and their bio-mineralization behavior was investigated. The films were composed mainly of TiO2 phases in the form of anatase and rutile and enriched with Ca and P elements in the form of CaTiO3 and amorphous calcium phosphate. Their bio-mineralization behavior was evaluated in a simulated body fluid (SBF). After immersed in SBF for 72 h, white mineralized layers were observed on the samples obtained at high voltages. The bio-mineralized rate of samples increased with the applied voltages, which resulted in the difference on morphology of different samples. The structure and composition of the films have an important effect on their bio-mineralization behavior.


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