Preparation and Properties of Fluoride-Coated Mg-Zn-Zr Alloy for Biodegradable Intravascular Stents

2011 ◽  
Vol 287-290 ◽  
pp. 1970-1975
Author(s):  
Xin Yu Ye ◽  
Min Fang Chen ◽  
De Bao Liu ◽  
Meng Yang ◽  
Jun Wei
Keyword(s):  
Corrosion Resistance ◽  
Fine Particles ◽  
Corrosion Current ◽  
Cell Number ◽  
Electrochemical Tests ◽  
In Vitro Biocompatibility ◽  
Intravascular Stents ◽  
Surface Morphologies ◽  
Zr Alloy

In order to improve the corrosion resistance, the samples made of Mg-Zn-Zr alloy were immersed in 20% or 40% hydrofluoric acid (HF) aqueous solutions for different intervals to prepare magnesium fluoride (MgF2) coating on the surface. By comparing the surface morphologies, the samples immersed in 20% HF solution for 6 h on which fine particles in nanoscale covered was selected for the further study. Immersion and electrochemical tests showed that the dense MgF2 coating would improve the corrosion resistance of Mg-Zn-Zr alloy. The corrosion current density (icorr) decreased from 2.10 μA·cm-2 to 0.05 μA·cm-2. The influence of HF treatment on the cytocompatibility was evaluated in vitro. There were significant differences in the cell number between the naked and coated samples after culturing for 3 and 5 days (p<0.05). All the results demonstrate that HF treatment is a promising approach to improve the corrosion resistance and in vitro biocompatibility of Mg-Zn-Zr alloy used as intravascular stents.

scholarly journals Glass-Forming Ability and Corrosion Resistance of Al88Y8−xFe4+x (x = 0, 1, 2 at.%) Alloys

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1581
Author(s):  
Rafał Babilas ◽  
Monika Spilka ◽  
Katarzyna Młynarek ◽  
Wojciech Łoński ◽  
Dariusz Łukowiec ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Analytical Techniques ◽  
Corrosion Current ◽  
Glass Forming Ability ◽  
Electrochemical Tests ◽  
Glass Forming ◽  
Transmission Electron ◽  
Composition And Structure ◽  
Amorphous Structures ◽  
The Impact

The effect of iron and yttrium additions on glass forming ability and corrosion resistance of Al88Y8-xFe4+x (x = 0, 1, 2 at.%) alloys in the form of ingots and melt-spun ribbons was investigated. The crystalline multiphase structure of ingots and amorphous-crystalline structure of ribbons were examined by a number of analytical techniques including X-ray diffraction, Mössbauer spectroscopy, and transmission electron microscopy. It was confirmed that the higher Fe additions contributed to formation of amorphous structures. The impact of chemical composition and structure of alloys on their corrosion resistance was characterized by electrochemical tests in 3.5% NaCl solution at 25 °C. The identification of the mechanism of chemical reactions taking place during polarization test along with the morphology and internal structure of the surface oxide films generated was performed. It was revealed that the best corrosion resistance was achieved for the Al88Y7Fe5 alloy in the form of ribbon, which exhibited the lowest corrosion current density (jcorr = 0.09 μA/cm2) and the highest polarization resistance (Rp = 96.7 kΩ∙cm2).

Characterization of NiCrMo Dental Restoration Alloy

2021 ◽  
Vol 875 ◽  
pp. 373-378
Author(s):  
Ali Haider ◽  
Omar Farooq Azam ◽  
Muhammad Talha ◽  
Saleem Akhtar
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Dental Materials ◽  
Dental Restoration ◽  
Restorative Material ◽  
Nicr Alloy ◽  
In Vitro Biocompatibility ◽  
Dental Prostheses ◽  
Materials Used

Restorative material is a class of dental materials used for direct filling and fabrication of indirect restoration. NiCr alloy is a restorative material frequently used for dental prostheses due to its properties and economic reasons. In present work beryllium free NiCrMo alloy was developed and studied for dental restoration application. The alloy have unique characteristics of resistance to oxidation and biocompatibility; the requisites for dental prostheses. NiCrMo alloy is found to possess mechanical strength and fabrication properties suitable for dental repairs. In this study the developed alloy was tested for its mechanical properties, biocompatibility and corrosion resistance. An in-vitro biocompatibility study was carried out. No signs of toxicity and no signs of cell growth inhibition, in presence of NiCrMo alloy specimen, were observed. Mechanical properties and corrosion resistance are found in the range that is suitable for dental prostheses and easy fabrication.

Electroless Multilayer Coatings Used in the Protection of Thermosyphon Economizer from Corrosion

2012 ◽  
Vol 512-515 ◽  
pp. 1607-1610
Author(s):  
Yang Xu ◽  
Yong Zou ◽  
Tao Luan
Keyword(s):  
Corrosion Resistance ◽  
Single Layer ◽  
Electroless Nickel ◽  
Corrosion Current ◽  
Multilayer Coatings ◽  
Electrochemical Tests ◽  
Exhaust Temperature ◽  
Electroless Copper ◽  
Save Energy ◽  
Better Than

Economizers are widely employed in the boiler system to increase efficiency and save energy. However one prominent problem is the severe corrosion of economizer due to the decrease of the exhaust temperature of boiler. Ni–P/Cu/Ni-P multilayer coatings, which could effectively improve the corrosion resistance of the facilities in economizer, are introduced in the present work. The three-layer coatings, whose composition is Ni–P/Cu/Ni-P from substrate to surface, were prepared using dual baths (acidic hypophosphite-reduced electroless nickel bath and acidic replacement electroless copper bath). The corrosion resistance of the coatings was evaluated by porosity and electrochemical tests. The results of porosity evaluation show that all the multilayer coatings performed better than the single-layer coatings of similar thickness. Similarly, The electrochemical tests showed lower corrosion current density for the multilayer coatings in 3.5 wt.% NaCl aqueous solutions.

Corrosion behavior of rare earth modified WC-12Co coating

2015 ◽  
Vol 29 (10n11) ◽  
pp. 1540029 ◽  
Author(s):  
Yan Liu ◽  
Hui Chen ◽  
Shengbo Ceng ◽  
Guoqing Gou ◽  
Mingjing Tu
Keyword(s):  
Corrosion Resistance ◽  
Rare Earth ◽  
High Speed ◽  
Interfacial Strength ◽  
Binder Phase ◽  
Hvof Spraying ◽  
Electrochemical Tests ◽  
Corrosion Mechanisms ◽  
Performance Results ◽  
Surface Morphologies

Rare earth has been widely used in materials manufacturing to improve hardness and toughness. In this paper, conventional, nano-modified and CeO 2 modified WC-12Co coatings are produced by using high speed oxygen flaming (HVOF) spraying technology. Long-term immersion and electrochemical tests of these coatings in 3.5 wt.% NaCl solution are conducted. The surface morphologies were observed to investigate the corrosion mechanisms. The results show CeO 2 modified WC-12Co coatings to possess the best corrosion resistance but the nano-modified WC-12Co coating has the worst performance. Results suggest that the improvement of corrosion resistance for CeO 2 modified WC-12Co coating can be attributed to the enhancement of interfacial strength between Co binder phase and WC particles.

Synthesis and Characterization of Chrom-Free Dark Coating on AA6063 Aluminium Alloy with K2ZrF6

2014 ◽  
Vol 1053 ◽  
pp. 421-428
Author(s):  
Ting Yi Chen ◽  
Ye Qi Fu ◽  
Wen Lu ◽  
Wen Fang Li
Keyword(s):  
Corrosion Resistance ◽  
Aluminium Alloy ◽  
Corrosion Current ◽  
Visual Assessment ◽  
Electrochemical Analysis ◽  
Conversion Coating ◽  
Electrochemical Tests ◽  
Excellent Corrosion Resistance ◽  
New Treatment

A new passivation process has been developed for producing a chrome-free and coloured conversion coating on aluminium alloy AA6063 with K2ZrF6. The conversion coating obtained has a dark film, which enables visual assessment of the coating development and coating quality during processing. The colouring effect is a significant advantage over the zirconium based conversion coatings currently used in the industry, which are largely colourless. The new treatment process is simple and allows a uniform coating to be formed within a few minutes. The composition and the surface morphology of the coatings were characterized. The corrosion resistance of the coated samples was evaluated by electrochemical tests. Through electrochemical analysis, corrosion current of the coatings is low, it has excellent corrosion resistance; SEM, EDS and XRD are used to analyze the process coating.

In vitro biocompatibility and corrosion resistance of a new implant titanium base alloy

2010 ◽  
Vol 21 (6) ◽  
pp. 1959-1968 ◽  
Author(s):  
E. Vasilescu ◽  
P. Drob ◽  
D. Raducanu ◽  
V. D. Cojocaru ◽  
I. Cinca ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Base Alloy ◽  
In Vitro Biocompatibility

scholarly journals Surface Characterization, Corrosion Resistance and in Vitro Biocompatibility of a New Ti‐Hf‐Mo‐Sn Alloy

Materials ◽  
2016 ◽  
Vol 9 (10) ◽  
pp. 818 ◽  
Author(s):  
Raluca Ion ◽  
Silviu Drob ◽  
Muhammad Ijaz ◽  
Cora Vasilescu ◽  
Petre Osiceanu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Surface Characterization ◽  
In Vitro Biocompatibility

Preparation, Corrosion and Cytocompatability In Vitro of Fluoride-Coated Mg-Zn-Zr Alloy

2016 ◽  
Vol 852 ◽  
pp. 1293-1299
Author(s):  
Hao Ran Zheng ◽  
Jing Zhang ◽  
Chen You ◽  
Min Fang Chen
Keyword(s):  
Aqueous Solution ◽  
Corrosion Resistance ◽  
Body Fluid ◽  
Immersion Time ◽  
Processing Time ◽  
Corrosion Potential ◽  
Solution Treatment ◽  
Good Biocompatibility ◽  
Zr Alloy

The present investigation was carried out to optimize the hydrogen fluoride (HF) aqueous solution treatment for an Mg-2.5Zn-0.5Zr alloy, in order to improve the corrosion resistance of the material for orthopaedic applications. An MgF2 coating was formed on the surface of Mg-2.5Zn-0.5Zr alloy treated with HF solution. The effect of the HF concentration and processing time on the morphology and electrochemical performance of the MgF2 coating was systematically studied. The results showed that the MgF2 coating became thick gradually with the increase of the concentration of HF solution. However, the pinhole on the surface treated with 40% HF increased significantly. The coating thickness immersed in the same concentration of HF solution increased with immersion time, and cracks formed in the surface after four hours of immersion, resulting in a decrease in the corrosion potential. When the alloy was immersed in the HF solution with a concentration 20% at 37°C for 2h, a uniform and dense fluoride coating was formed, with a thickness of MgF2 layer of about 0.5μm. The corrosion potential of the coated Mg alloy in simulated body fluid (SBF) was 0.28V higher than the uncoated one. In addition, the fluoride-coated showed a good biocompatibility.

Sign in / Sign up

Export Citation Format

Share Document