scholarly journals Enhanced corrosion resistance and surface bioactivity of AZ31B Mg alloy by high pressure cold sprayed monolayer Ti and bilayer Ta/Ti coatings in simulated body fluid

2020 ◽  
Vol 256 ◽  
pp. 123627
Author(s):  
M. Daroonparvar ◽  
M.U. Farooq Khan ◽  
Y. Saadeh ◽  
C.M. Kay ◽  
R.K. Gupta ◽  
...  
Keyword(s):  
High Pressure ◽  
Corrosion Resistance ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Mg Alloy

In Vitro Degradation of Ultrafine Grained Mg-Zn-Ca Alloy by High-Pressure Torsion in Simulated Body Fluid

2012 ◽  
Vol 706-709 ◽  
pp. 504-509 ◽  
Author(s):  
Shao Kang Guan ◽  
Zhen Wei Ren ◽  
Jun Heng Gao ◽  
Yu Feng Sun ◽  
Shi Jie Zhu ◽  
...  
Keyword(s):  
High Pressure ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
High Pressure Torsion ◽  
Cast Alloy ◽  
Mg Alloy ◽  
Second Phase ◽  
Ultrafine Grained ◽  
Degradation Properties

In this paper the in vitro degradation of ultrafine grained (UFG) Mg-Zn-Ca alloy produced by HPT was investigated by electrochemical measurements and immersion tests in SBF. It was found that UFG Mg alloy had better degradation properties and also higher microhardness value than as-cast Mg alloy. The corrosion current density of UFG Mg alloy decreased by about two orders of magnitude, compared with that of as-cast alloy. Through electrochemical impedance spectroscopy (EIS) test，UFG Mg alloy showed a higher charge transfer resistance value. In immersion test, UFG Mg alloy in SBF exhibited more uniform corrosion and lower degradation rate (0.0763 mm/yr) than as-cast alloy. The degradation properties were related with the microstructure evolution, namely the grain refinement and redistribution of second phase. Keywords: Mg-Zn-Ca alloy; High-pressure torsion (HPT); Degradation behavior; Simulated body fluid (SBF); Microhardness

Microstructural Changes of AZ31 Magnesium Alloys Induced by Cryogenic Machining and Its Influence on Corrosion Resistance in Simulated Body Fluid for Biomedical Applications

2010 ◽  
Author(s):  
Z. Pu ◽  
O. W. Dillon ◽  
I. S. Jawahir ◽  
D. A. Puleo
Keyword(s):  
Corrosion Resistance ◽  
Simulated Body Fluid ◽  
Magnesium Alloys ◽  
Body Fluid ◽  
Bulk Material ◽  
White Layer ◽  
Cutting Speed ◽  
Mg Alloy ◽  
Cryogenic Machining ◽  
Az31 Mg Alloy

Poor corrosion resistance is one of the major disadvantages of magnesium alloys that inhibits their wide application. It was reported frequently that the alloys’ microstructure has a significant influence on their corrosion resistance. In this study, cryogenic machining is used as a severe plastic deformation tool to modify the surface and subsurface microstructures of an AZ31 Mg alloy. Liquid nitrogen is applied to suppress grain growth caused by large heat generation during machining. “White layers”, where grain boundaries were invisible, were shown to form on the surface and subsurface after machining. The hardness of this layer was about 60% larger than the bulk material. The tool edge radius and the cutting speed have profound influence on the microstructures. Preliminary results from immersion tests in simulated body fluid showed that the corrosion resistance of the AZ31 Mg alloy was enhanced due to the formation of white layer.

Evaluation of the Bioactivity Behavior of a 48 Wt %SiO2 Bioglass through Experiments in Simulated Body Fluid

2012 ◽  
Vol 727-728 ◽  
pp. 1238-1242 ◽  
Author(s):  
Roger Borges ◽  
Antônio Carlos da Silva ◽  
Juliana Marchi
Keyword(s):  
Corrosion Resistance ◽  
Surface Layer ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Glass Network ◽  
In Vitro Experiments ◽  
High Corrosion Resistance ◽  
Before And After ◽  
O 19

Among bioceramics materials, bioglasses which exhibits either a bioactive or resorbable behavior has been studied for many applications, such as bone substitutive and regeneration. When in contact with body fluid, the bioglasses can induce the formation of a hydroxyapatite surface layer. In this paper, we studied the bioactivity of a bioglass containing 48 wt %SiO2, 27 wt% Na2O, 19 wt % CaO and 6 wt %P2O5. After fusion and annealing, the samples were immersed in SBF for different periods, up to 14 days. The samples were characterized through XRD, DRIFT and SEM before and after bioactivity experiments. The overall results suggest the formation of a surface layer of consisting of hydroxyapatite, which was crystallized within seven days after in vitro experiments, leading to a suitable bioactivity. Moreover, the samples showed a glass network with high cohesion due to calcium addition, leading to materials with high corrosion resistance.

Studies on Development, Bioactivity and Corrosion Behaviour of Nanostructured Titania/Hydroxyapatite Composite Layer on Cp Ti

2011 ◽  
Vol 471-472 ◽  
pp. 325-330 ◽  
Author(s):  
K. Venkateswarlu ◽  
N. Rameshbabu ◽  
Arumugam Chandra Bose ◽  
V. Muthupandi ◽  
S. Subramanian
Keyword(s):  
Corrosion Resistance ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Composite Layer ◽  
In Vitro Bioactivity ◽  
X Ray ◽  
Composite Layers ◽  
Cp Ti ◽  
Nanostructured Titania

Nanostructured titania/hydroxyapatite (HA) composite layer was developed on commercially pure titanium (Cp Ti) implant material by plasma electrolytic processing (PEP) technique in order to improve its bioactivity and corrosion resistance under physiological conditions. The phases present in the developed composite layer were studied by X-ray diffraction (XRD) technique. The surface morphology and thickness of the composite layers were observed by scanning electron microscopy (SEM). The corrosion characteristics of the developed layer were studied by potentiodynamic polarization scan under simulated body fluid (7.4 pH Hanks solution) and simulated osteoclast (4.5 pH) conditions. The in-vitro bioactivity of the composite layers was studied by using Kokubu’s simulated body fluid (SBF) solution. The X-ray diffractograms reveal the presence of anatase TiO2 and HA phases in the developed layer. The SEM results confirm the pore-free morphology of the implant material surface and the thickness of the developed composite layer was observed to be 110 ± 5 µm for 12 min of PEP. The potentiodynamic polarization study shows an improved corrosion resistance and the in-vitro bioactivity test results indicate enhanced apatite forming ability of PEP treated Cp Ti surfaces compared to that of the untreated Cp Ti, under simulated body fluid conditions.

scholarly journals Effect of Zn Content on Orthopedic Mg aAlloy as Smart Implant

2020 ◽  
Vol 71 (6) ◽  
pp. 96-110
Author(s):  
Omyma Ramadan Mohammed Khalifa ◽  
Abdel-Wahab Abd Elhamid Ali ◽  
Aisha Kassab ◽  
Amal Hemida Tilp ◽  
Marwa Mohamed Mohamed Mohamed Esmail
Keyword(s):  
Corrosion Resistance ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Biomedical Applications ◽  
Orthopedic Implants ◽  
X Ray Diffraction ◽  
Electro Deposition ◽  
X Ray ◽  
Zn Content ◽  
The Media

In recent years, smart implants take the most attention in the field of bone manufacturing. Our study seeks to develop the biodegradability of Mg alloys to use orthopedic implants for the biomedical applications to avoid post removal of the implant. Mg and Zn are very important to human body and have no toxicity. Mg - 6% wt Zn biodegradability is studied in simulated body fluid for two and four weeks. Four electro-deposition bathes are used to deposit a coat on the substrate to improve the corrosion resistance of this alloy in the media of simulated body fluid. The following analyses were studied to emphasize the research aim. Scanning electron microscope (SEM), Energy dispersive X-Ray (EDX) analysis shows the surface morphology and the elements of the coat phases components. The results also confirmed by X-Ray diffraction Pattern (XRD) that show the phases that confirmed the formation of hydroxyapatite HA phase, Fourier-Transform Infrared Spectroscopy (FTIR) to investigate the functional groups of the phases coats that confirm the formation of hydroxyapatite and the electrochemical measurements that investigate the improvement of corrosion resistance. The results indicated that the fourth bath gives the best coat and four weeks immersion gives more corrosion resistance than two weeks.

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