Analysis of corrosion behaviour and surface properties of plasma-sprayed composite coating of hydroxyapatite–tantalum on biodegradable Mg alloy ZK60

2019 ◽  
Vol 53 (19) ◽  
pp. 2661-2673 ◽  
Author(s):  
Balraj Singh ◽  
Gurpreet Singh ◽  
Buta Singh Sidhu
Keyword(s):  
Corrosion Resistance ◽  
Surface Properties ◽  
Corrosion Behaviour ◽  
Surface Hardness ◽  
Mg Alloy ◽  
Hydroxyapatite Coating ◽  
Hydroxyapatite Coatings ◽  
Plasma Sprayed ◽  
Incremental Increase

Magnesium (Mg) and its alloys are promising candidates for biodegradable bio-implants. However, the excessive corrosion in the physiological environment and subsequent decline in the mechanical integrity of Mg and its alloys have limited their utility as biomaterials. In the present study, an attempt has been made to improve the corrosion resistance of Mg alloy ZK60 plasma sprayed with tantalum (Ta)-reinforced hydroxyapatite coating. The experiment was conducted with three varied levels, i.e. 10, 20 and 30 weight percent (wt%) of Ta-content in hydroxyapatite coating. The coatings were characterized and in vitro corrosion behaviour was investigated by electrochemical measurements in Ringer's solution along with the analysis of surface properties. The corrosion resistance of the Mg alloy increased with the incremental increase in Ta reinforcement in hydroxyapatite coating. An increase in the protection efficiency was analysed for the Ta-reinforced hydroxyapatite coatings (∼10%, 18% and 23% for hydroxyapatite-10Ta, hydroxyapatite-20Ta and hydroxyapatite-30Ta, respectively) as compared to the pure hydroxyapatite coating. The hydroxyapatite coating effectively increased the surface hardness of the Mg alloy and Ta reinforcement further enhanced it. Surface roughness decreased with the incremental increase in Ta-content in hydroxyapatite coating. Wettability analysis revealed the hydrophilic nature of pure hydroxyapatite and Ta-reinforced hydroxyapatite coatings. The results of the study suggest that the proposed Ta reinforcement in hydroxyapatite is potentially important for biodegradable Mg bio-implants.

In vitro andin vivo biological responses of plasma-sprayed hydroxyapatite coatings with posthydrothermal treatment

2007 ◽  
Vol 83A (2) ◽  
pp. 263-271 ◽  
Author(s):  
C. Y. Yang ◽  
T. M. Lee ◽  
C. W. Yang ◽  
L. R. Chen ◽  
M. C. Wu ◽  
...  
Keyword(s):  
Biological Responses ◽  
Hydroxyapatite Coatings ◽  
Plasma Sprayed

In Vitro Assessment of Hydroxyapatite and Si-Substituted Hydroxyapatite Coatings under Different VPS Conditions

2008 ◽  
Vol 396-398 ◽  
pp. 345-348 ◽  
Author(s):  
Qian Tang ◽  
Roger Brooks ◽  
Serena Best
Keyword(s):  
Input Power ◽  
Precipitation Method ◽  
Human Osteoblast ◽  
Lower Plasma ◽  
Plasma Gun ◽  
Vacuum Plasma ◽  
Hydroxyapatite Coatings ◽  
Phase Pure ◽  
Plasma Sprayed

Hydroxyapatite and silicon-substituted hydroxyapatite powers were prepared in-house through a wet precipitation method and then vacuum plasma sprayed onto Ti-6Al-4V discs. Two plasma gun input powers were employed, 37 kW and 40 kW. All coatings were nearly phase pure, except small traces of impurities (TTCP, -TCP and CaO). Coatings prepared under the lower plasma gun input power had lower crystallinity. In vitro studies showed that human osteoblast-like cells attached and spread very well on all coated discs. Among the four kinds of discs, SiHAC37 was the most supportive to cell growth.

Electrochemical Determination of the Corrosion Resistance of Ag-Pd Dental Alloys

2008 ◽  
Vol 59 (9) ◽  
Author(s):  
Daniel Mareci ◽  
Igor Cretescu ◽  
Neculai Aelenei ◽  
Julia Claudia Mirza Rosca
Keyword(s):  
Corrosion Resistance ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Artificial Saliva ◽  
Surface Film ◽  
Electrochemical Determination ◽  
Open Circuit ◽  
Electrochemical Characteristics

The electrochemical behavior of a three Ag-Pd alloys used in dental prosthetics construction for crowns and bridges was studied in artificial saliva using the polarization curves and electrochemical impedance spectroscopy (EIS). The corrosion resistance was evaluated by means of the corrosion currents value and by coulometric analysis. The open circuit potential of Ag-Pd are attributed to dealloying followed by surface enrichment with Ag and the possible formation of an insoluble AgCl surface film on the respective alloy surfaces. Our results have shown that these alloys have a somewhat good corrosion resistance in artificial saliva. When increasing the content of Cu, corrosion resistance decreases. The passivation of all samples occurred spontaneously at the open circuit potential. The electrochemical properties of the spontaneously passivated electrodes at the open circuit potential were studied by EIS. The polarization resistance (Rp) and the electrode capacitance (Cdl) were determined. The polarisation resistance of all the samples increases with the immersion time. The polarization resistances are largest and decrease when increasing the content of Cu. Cu reduces the Ag-Pd alloy corrosion resistance. The present study, thought limited, has shown that electrochemical characteristics can be use to identify such alloys. Knowledge of the in vitro corrosion behaviour of these alloys may lead to better understanding of any biologically adverse effects in vitro.

Mg alloy surface immobilised with caerin peptides acquires enhanced antibacterial ability and improved corrosion resistance

2020 ◽  
Author(s):  
Tianfang Wang ◽  
Guoying Ni ◽  
Tsuyoshi Furushima ◽  
Hui Diao ◽  
Pingping Zhang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Antibacterial Effect ◽  
Click Reaction ◽  
Mg Alloys ◽  
Mg Alloy ◽  
Alloy Sample ◽  
Plasma Chemical ◽  
Antibacterial Ability ◽  
Comparison Results

Abstract Magnesium (Mg) has mechanical properties similar to human bones and Mg alloy is considered ideal medical implant material. However, the high velocity of degradation inside the human inner environment severely hampers the usage of Mg alloys. In this study, caerin peptide 1.9 (F3) and a modified sequence of caerin 1.1 (F1) with anti-bacterial activity, were covalently immobilised on the surface of Mg alloys by plasma chemical click reaction. The in vitro antibacterial activity and corrosion resistance of these caerin peptide-immobilised Mg alloys were investigated in Dulbecco's Modified Eagle Medium (DMEM) solution. Un-immobilised Mg alloy sample, blank drug-sensitive tablet (BASD) and a commonly used antibiotics Tazocin were used for comparison. Results showed that peptide immobilised Mg samples showed significant improved corrosion resistance and prolonged antibacterial effect compared to non-immobilised Mg alloy and free caerin peptides. Furthermore, annealing or extruding treatment of Mg alloys improved the behaviours of corrosion resistance and antibacterial property. These results indicate that coating Mg alloy with caerin peptides improves the corrosion resistance in vitro and increases the alloy’s antibacterial ability. The mechanism underlying the prolonged antibacterial effect for annealed Mg alloys immobilised with the peptides (especially F3) remains unclear, which worth further experimental and theoretical investigation.

In Vitro Cytocompatibility of Silver-Containing Hydroxyapatite Coatings

2009 ◽  
Vol 620-622 ◽  
pp. 567-570 ◽  
Author(s):  
Yi Kai Chen ◽  
Xue Bin Zheng ◽  
Baoe Li ◽  
You Tao Xie ◽  
Chuan Xian Ding ◽  
...  
Keyword(s):  
Contact Angle ◽  
Antibacterial Property ◽  
Water Drop ◽  
Contact Angles ◽  
Hydroxyapatite Coating ◽  
Vacuum Plasma Spraying ◽  
Vacuum Plasma ◽  
Hydroxyapatite Coatings ◽  
Spraying Method

In this paper, antibacterial silver-containing hydroxyapatite coating was prepared by vacuum plasma spraying method and osteoblasts were seeded onto the surface of the coating to evaluate its cytocompatibility. The results indicated that the cells proliferated well on the samples, and the proliferation rate on the silver-containing hydroxyapatite coating was a little bit higher than that on the silver-free hydroxyapatite coating. The contact angle of water drop on the coating was measured, and it was found that the contact angles of the silver-containing hydroxyapatite coatings were smaller than the hydroxyapatite coating. The improvement of hydrophilicity for the silver-containing hydroxyapatite coating could be beneficial to the cells proliferation on its surface. It can be concluded that the addition of silver in the hydroxyapatite coating endowed the coating with antibacterial property while maintaining its excellent cytocompatibility.

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