Study on the Corrosion Behavior In Vitro and Mechanical Properties of the FHA Coated Mg-Zn-Zr Alloy

2016 ◽  
Vol 849 ◽  
pp. 647-653 ◽  
Author(s):  
C.G. Li ◽  
Min Fang Chen ◽  
S.Z. Sun ◽  
J. Zhang

The fluorine-doped hydroxyapatite (FHA) coating on the surface of Mg-3wt%Zn-0.8wt%Zr alloy was prepared using a chemical treatment method. The standard tensile samples of coated and uncoated Mg alloy were immersed in the SBF respectively for 1,3,5,10,20 and 30 days. The effect of the FHA coating on corrosion behavior in vitro and mechanical properties of the Mg-Zn-Zr alloy was investigated. Based on the losing weight and the max corrosion depth of the samples, the corrosion rate can be calculated. According to the weightlessness curve of samples, the average corrosion rate of the bare alloy, the alloy of MgF2 coating and the alloy of FHA coating were 4.13mm / y, 1.51mm / y and 0.86mm / y within 30 days in vitro, respectively. It can be seen that the significant difference of mechanical properties between the coated and uncoated samples with the increase of immersing time. This fully revealed that the FHA coating on the Mg-Zn-Zr alloy is beneficial to improve its corrosion resistance.

Author(s):  
Jie Teng ◽  
Zili Xu ◽  
Jinlong Su ◽  
Yuan Li

Abstract In this study, hydroxyapatite-reinforced ZK60 Mg alloybased composites were fabricated via a powder metallurgy route. The mechanical properties of these composites were studied by compressive tests and hardness tests. The in-vitro corrosion behavior was also investigated using immersion testing and electrochemical measurement. The influence of hydroxyapatite content on the mechanical properties and invitro corrosion behavior was evaluated. The microstructure and corrosion morphology were characterized by means of X-ray diffraction, optical and scanning electron microscopy. The results showed that the composite materials with 10 wt.% hydroxyapatite exhibited a better combination of mechanical strength and corrosion resistance. Compared with ZK60 alloy, the addition of 10 wt.% hydroxyapatite resulted in an increase in corrosion resistance by 38.6%.


Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 505
Author(s):  
Krzysztof Aniołek ◽  
Bożena Łosiewicz ◽  
Julian Kubisztal ◽  
Patrycja Osak ◽  
Agnieszka Stróż ◽  
...  

Titanium and its alloys are among the most promising biomaterials for medical applications. In this work, the isothermal oxidation of Ti-6Al-7Nb biomedical alloy towards improving its mechanical properties, corrosion resistance, and bioactivity has been developed. The oxide layers were formed at 600, 700, and 800 °C for 72 h. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), 3D profilometry, and microindentation test, were used to characterize microstructure, surface geometrical structure, and the hardness of the diphase (α + β) Ti-6Al-7Nb alloy after oxidation, respectively. In vitro corrosion resistance tests were carried out in a saline solution at 37 °C using the open-circuit potential method and potentiodynamic measurements. Electronic properties in the air were studied using the Scanning Kelvin Probe (SKP) technique. The bioactivity test was conducted by soaking the alkali- and heat-treated samples in simulated body fluid for 7 days. The presence of apatite was confirmed using SEM/EDS and Fourier Transform Infrared Spectroscopy (FTIR) studies. The thickness of oxide layers formed increased with the temperature growth from 0.25 to 5.48 µm. It was found that with increasing isothermal oxidation temperature, the surface roughness, hardness, corrosion resistance, and contact potential difference increased. The Ti-6Al-7Nb alloy after oxidation revealed the HAp-forming ability in a biological environment.


2016 ◽  
Vol 103 ◽  
pp. 10-24 ◽  
Author(s):  
A.R. Rafieerad ◽  
A.R. Bushroa ◽  
B. Nasiri-Tabrizi ◽  
J. Vadivelu ◽  
S. Baradaran ◽  
...  

2021 ◽  
Vol 21 (4) ◽  
pp. 2221-2233
Author(s):  
Yaru Liu ◽  
Qinglin Pan ◽  
Xiangdong Wang ◽  
Ye Ji ◽  
Qicheng Liu ◽  
...  

The corrosion mechanisms for different corrosive media on the aged 7A46 aluminum alloy were systematically investigated at nanoscale level. The combination of empirical intergranular and exfoliation corrosion behavior was employed, and coupled with first-principles calculations. Results revealed that the dispersed distribution of matrix precipitates (MPs) leads to the enhancement of the corrosion resistance pre-ageing (PA) followed by double-ageing (PA-DA) alloy. The deepest corrosion depth of PA-DA alloy was in hydrochloric acid, and the calculation result demonstrates that the passivation effect in combination with the accumulation of corrosion products in nitric acid protect the PA-DA alloy from further corrosion.


2021 ◽  
Vol 875 ◽  
pp. 373-378
Author(s):  
Ali Haider ◽  
Omar Farooq Azam ◽  
Muhammad Talha ◽  
Saleem Akhtar

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.


10.30544/403 ◽  
2018 ◽  
Vol 24 (4) ◽  
Author(s):  
Tamara Matic ◽  
Maja Ležaja Zebić ◽  
Ivana Cvijović-Alagić ◽  
Vesna Miletić ◽  
Rada Petrović ◽  
...  

The aim of this study was to investigate the possibility of modifying model BisGMA/TEGDMA dental composite by substituting 10 wt. % of conventional glass fillers with bioactive fillers based on calcinated nanosized hydroxyapatite (HAp) and Mg doped hydroxyapatite (Mg-HAp). HAp and Mg-HAp powders were synthesized hydrothermally. Mechanical properties: hardness by Vickers (HV) and flexural strength (Fs) were tested initially and after being stored for 28 days in simulated body fluid (SBF). The experimental composites with HAp and Mg-HAp particles showed no statistically significant difference in HV compared to the control (p>0.05) either initially or after storage. Although mean Fs values of modified composites tested initially were lower (62 MPa) than those of the control (72 MPa), after 28 days of storage in SBF Fs values were greater for modified composites (42 MPa control sample, 48 MPa HAp and Mg-HAp samples). In vitro bioactivity of BisGMA/TEGDMA composites with HAp and Mg-HAp particles after 28 days in SBF was not detected. Keywords: hydroxyapatite; magnesium; dental composite; mechanical properties;


1970 ◽  
Vol 25 ◽  
pp. 53-61
Author(s):  
Minu Basnet ◽  
Jagadeesh Bhattarai

The corrosion behavior of the sputter-deposited nanocrystalline W-Cr alloys wasstudied in 0.5 M NaCl and alkaline 1 M NaOH solutions at 25°C, open to air usingimmersion tests and electrochemical measurements. Chromium metal acts synergisticallywith tungsten in enhancing the corrosion resistance of the sputter-deposited W-Cr alloys soas to show higher corrosion resistance than those of alloy-constituting elements in both 0.5M NaCl and 1 M NaOH solutions. In particular, the nanocrystalline W-Cr alloys containing25-91 at% chromium showed about one order of magnitude lower corrosion rates (that is,about 1-2 × 10-3 mm.y-1) than those of tungsten and chromium metals even for prolongedimmersion in 0.5 M NaCl solution at 25°C. On the other hand, the corrosion rate of thesputter-deposited W-Cr alloys containing 25-75 at % chromium was decreased significantlywith increasing chromium content and showed lowest corrosion rates (that is, 1.5-2.0 × 10-3 mm.y-1) after immersed for prolonged immersion in 1 M NaOH solution. The corrosion ratesof these nanocrystalline W-(25-75)Cr alloys are nearly two orders of magnitude lower thanthat of tungsten and more than one order of magnitude lower corrosion rate than that ofsputter-deposited chromium metal in 1 M NaOH solution. The corrosion-resistant of all theexamined sputter-deposited W-Cr alloys in 0.5 M NaCl solution is higher than in alkaline 1M NaOH solution at 25°C. Open circuit potentials of all the examined W-Cr alloys areshifted to more noble direction with increasing the chromium content in the alloys afterimmersion for 72 h in both 0.5 M NaCl and 1 M NaOH solutions at 25°C, open to air.Keywords: Sputter deposition, nanocrystalline W-Cr alloys, corrosion test, electrochemicalmeasurement, NaCl and NaOH solutions.DOI:  10.3126/jncs.v25i0.3300Journal of Nepal Chemical Society Volume 25, 2010 pp 53-61


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