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1.
The chemical and physical processes of magnesium in simulated body fluid (SBF) were investigated. The corrosion rate of magnesium was measured after 3, 5, 7, 14 and 21 days of immersion, respectively. It was found that the corrosion rate decreased with increasing immersion time, while the pH of SBF changed inversely. Network-like cracks and pits were the main damages resulting from corrosion, and the localized buildup of chloride ions was the major cause of pit formation. 相似文献
2.
R. WalterM. Bobby Kannan 《Materials Letters》2011,65(4):748-750
Rare earths containing magnesium alloy, WE54, exhibited a marginally higher in-vitro degradation resistance than that of pure magnesium. Heat-treatment procedure had an influence on the degradation behaviour. However, comparing with AZ91 magnesium alloy the in-vitro degradation resistance of WE54 magnesium alloy was significantly lower, which suggests that the passivating capacity of rare earths is inferior to that of aluminium under in-vitro condition. 相似文献
3.
Yongsheng WangChu Sing Lim Chao Voon LimMing Shyan Yong Eng Kiong TeoLaw Ngai Moh 《Materials science & engineering. C, Materials for biological applications》2011,31(3):579-587
Magnesium alloys possess unique advantages to be used as biodegradable implants for clinical applications. In this study, in vitro cells responses and degradation behaviors of magnesium alloy M1A in simulated body fluid (SBF) and albumin-containing SBF (A-SBF) were systematically investigated. Cell responses, in terms of Cell morphology and cell proliferation, imply that M1A possesses good viability for MG63 cells. The corrosion behaviors of M1A are strongly affected by the addition of albumin through the combined effects of adsorption and chelation. Electrochemical testing indicates that such an absorbed albumin layer makes M1A to be more noble with a smaller corrosion current. Corrosion rate monitored by hydrogen evolution rate suggests that the quickly adsorbed albumin serves as an effective protective layer, resulting in a much slower hydrogen release rate at initial stage. With increasing immersion time, a higher corrosion rate is observed since the chelation effect exerts more significant acceleration effects on the removal of the passivation layer. The corrosion mode evaluated by surface morphology of the samples changes from a nonuniform-anisotropic mode for M1A in SBF to a uniform-isotropic mode for M1A in A-SBF. 相似文献
4.
Electrochemical behavior of biocompatible AZ31 magnesium alloy in simulated body fluid 总被引:1,自引:0,他引:1
Dense oxidation coatings have been successfully developed on biocompatible AZ31 magnesium alloy, using microarc oxidation
technique, to improve the corrosion resistance. Three different deposition voltages of 250, 300, and 350 V have been employed.
The effect of voltage on the coating corrosion resistance has been evaluated through electrochemical experiments in a simulated
body fluid (SBF) up to 7 days. Potentiodynamic polarization and electrochemical impedance spectroscopy scans were performed
in the SBF solution, followed by optical microscopy surface inspection. The results indicate that the corrosion rates of the
coatings are in the order of 250 < 300 < 350 V after immersion for 7 days, and the charge transfer resistance (R
ct) of the three samples is in the order of 250 > 300 > 350 V. Both the electrochemical tests and the surface inspection suggest
that the 250 V coating has the highest corrosion resistance, with lowest corrosion current density, highest R
ct, and the best surface quality. 相似文献
5.
Durga Bhakta Pokharel Liping Wu Junhua Dong Xin Wei Ini-Ibehe Nabuk Etim Dhruba Babu Subedi Aniefiok Joseph Umoh Wei Ke 《材料科学技术学报》2021,66(7):202-212
The effect of addingd-fructose to simulated body fluid(SBF) on the corrosion behavior of AZ31 magnesium(Mg) alloy at 37.C and at a pH of 7.4 was studied by potentiodynamic polarization(PDP), electrochemical impedance spectroscopy(EIS), potentiostatic polarization and hydrogen(H2) collecting techniques,Raman spectroscopy technique, scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), X-ray diffraction(XRD), X-ray photoelectron spectroscopy analysis(XPS) and Fourier transformed infrared(FTIR). The results demonstrated that the addition of fructose enhanced the deposition of phosphates forming thick and compact corrosion products, which inhibited the transmission of aggressive ions into the Mg substrate. As a result, both the anodic dissolution of Mg and negative difference effect(NDE) were suppressed. Thus, the corrosion resistance of AZ31 Mgalloy in SBF was significantly improved. 相似文献
6.
Lijun Liu Yao Meng Chaofang Dong Yu Yan Alex A. Volinsky Lu-Ning Wang 《材料科学技术学报》2018,34(12):2271-2282
Zinc was recently suggested to be a potential candidate material for degradable coronary artery stent. The corrosion behavior of pure zinc exposed to r-SBF up to 336?h was investigated by electrochemical measurements and immersion tests. The morphology and chemical composites of the corrosion products were investigated by scanning electron microscope, grazing-incidence X-ray diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared spectrometer. The results demonstrate that the initial corrosion products on the pure zinc mainly consist of zinc oxide/hydroxide and zinc/calcium phosphate compounds. The pure Zn encounters uniform corrosion with an estimated corrosion rate of 0.02–0.07?mm?y?1 during the immersion, which suggests the suitability of pure Zn for biomedical applications. 相似文献
7.
8.
以AZ80A市售镁合金为参照,研究了镁基纳米复合材料镁,即:碳纳米管(Mg/CNT)复合材料及氧化镁(Mg/MgO)纳米复合材料在模拟体液中的腐蚀行为.浸泡过程中测量溶液的pH值变化,在浸泡1、4、8、10、20和30d后计算其腐蚀速率,并通过XRD分析腐蚀产物成分.结果显示:Mg/MgO纳米复合材料比Mg/CNT复合材料耐腐蚀,Mg/CNT复合材料在4d时已经腐蚀完,AZSOA型镁舍金最耐腐蚀。三者的腐蚀产物成分基本相同,均为Mg2CI(0H)3-4H2O及少量的MgCl2. 相似文献
9.
Yingwei Song Dayong Shan Rongshi Chen Fan Zhang En-Hou Han 《Materials science & engineering. C, Materials for biological applications》2009,29(3):1039-1045
Magnesium alloys have unique advantages to act as biodegradable implants for clinical application. The biodegradable behaviors of AZ31 in simulated body fluid (SBF) for various immersion time intervals were investigated by electrochemical impedance spectroscopy (EIS) tests and scanning electron microscope (SEM) observation, and then the biodegradable mechanisms were discussed. It was found that a protective film layer was formed on the surface of AZ31 in SBF. With increasing of immersion time, the film layer became more compact. If the immersion time was more than 24 h, the film layer began to degenerate and emerge corrosion pits. In the meantime, there was hydroxyapatite particles deposited on the film layer. The hydroxyapatite is the essential component of human bone, which indicates the perfect biocompatibility of AZ31 magnesium alloy. 相似文献
10.
Julia van Drunen Baodong Zhao Gregory Jerkiewicz 《Journal of Materials Science》2011,46(18):5931-5939
We investigate the influence of micro-sandblasting and electrochemical passivation on properties such as corrosion rate and
surface roughness, which are important to the biocompatibility of titanium (Ti), using surface analysis techniques and electrochemical
measurements. Results of microscopy and surface profilometry experiments reveal roughened but uniform surface topography with
an average surface roughness in the 0.87–1.06 μm range, depending on the alternating current passivation voltage applied to
the micro-sandblasted samples. Open circuit potential versus time measurements in Hank’s Balanced Salt Solution (HBSS, a simulated
body fluid) allow determination of the corrosion potential (E
corr) and reveal a shift of E
corr toward higher values upon passivation, thus pointing to increased corrosion stability. Corrosion rates in HBSS range between
0.049 and 0.288 μm year−1 for micro-sandblasted and passivated Ti, as compared to that for the micro-sandblasted and non-passivated surface that is
0.785 μm year−1. Results from this study demonstrate that micro-sandblasting coupled with electrochemical passivation provides a roughened
surface with increased corrosion stability and a low corrosion rate in HBSS. Application of this technique to Ti in medical
and dental applications may be expected to result in an improvement of biocompatibility. 相似文献
11.
Ying Xiong Yi Yu Jie Yang 《Fatigue & Fracture of Engineering Materials & Structures》2022,45(1):239-258
A bio-ceramic coating was prepared on the surface of ZK60 magnesium alloys by micro-arc oxidation (MAO) method. The substrate (BM) and coated (MAO) specimens were pre-corroded in a simulated body fluid (SBF) for 12 h. Strain-controlled and stress-controlled loading modes were used to conduct fatigue tests for the specimens with non-corroded and pre-corroded, and the cyclic deformation behavior of different specimens was studied. The fatigue life of pre-corroded MAO specimen is higher than that of pre-corroded BM specimen. The mechanism of cyclic deformation under different loading conditions is related to twinning and slip. For the same specimens, the higher the absolute value of ratcheting strain, the lower the fatigue life. A modified total strain energy model is proposed, and the precision of life prediction is higher than that of traditional fatigue model. 相似文献
12.
《材料科学技术学报》2019,35(11):2705-2713
In this study, the Zn-0.5 wt%Zr (Zn-Zr) alloy was treated by laser surface remelting (LSR), and then the microstructure and degradation mechanism of the remelting layer were investigated and compared with the original as-cast alloy. The results reveal that after LSR, the bulky Zn22Zr phase in the original Zn-Zr alloy is dissolved and the coarse equiaxed grains transform into fine dendrites with a secondary dendrite arm space of about 100 nm. During the degradation process in simulated body fluid (SBF), the corrosion products usually concentrate at some certain areas in the original alloy, while the corrosion products distribute uniformly and loosely in the LSR-treated surface. After removing the corrosion products, it was found that the former suffers obvious pitting corrosion and then localized corrosion. The proposed mechanism is that corrosion initiates at grain boundaries and develops into the depth at some locations, and then leads to localized corrosion. For the LSR-treated sample, corrosion initiates at some active sites and propagates in all directions, corrosion takes place in the whole surface with distinctly uniform thickness reduction, while the localized corrosion and peeling of bulky Zn22Zr particles were eliminated. The electrochemical results also suggest the uniform corrosion of LSR-treated sample and localized corrosion of original sample. Based on the results, a new approach to regulate the corrosion mode of the biodegradable Zn alloy is proposed. 相似文献
13.
Yong Wang Mei Wei Jiacheng Gao 《Materials science & engineering. C, Materials for biological applications》2009,29(4):1311-1316
A dicalcium phosphate dihydrate (DCPD) coating composed of bar-shaped crystals was deposited on the surface of magnesium in order to slow down the corrosion rate of the substrate. The corrosion resistance of the DCPD-coated specimens was evaluated in a simulated body fluid (SBF) with uncoated specimens as a control. Time-dependent characteristics of specimens and the corresponding SBF were analyzed at 3, 5, 7, 14 and 21 days of immersion. Less weight loss and pH increase were observed for the coated group than the uncoated group. The coating was intact after 3 days of immersion although its dissolution was manifested by XRD examination. Noticeable DCPD dissolution occurred at the 5th day accompanied by a temporary increase in Ca and P concentrations in SBF which otherwise kept decreasing. Despite the dissolution of the coating, some DCPD particles were still observed on the surface of the substrate after 21 days of immersion. In contrast to the coated specimens, a porous layer of Mg(OH)2 was formed on the surface of uncoated specimens at the 5th day of immersion. It was found that the corrosion rate of the coated group was substantially lower than that of the control. 相似文献
14.
Catalin Zaharia Mihaela-Ramona Tudora Izabela-Cristina Stancu Bianca Galateanu Adriana Lungu Corneliu Cincu 《Materials science & engineering. C, Materials for biological applications》2012,32(4):945-952
This paper reports the mineralization ability of semi-interpenetrating networks composed of regenerated silk fibroin and polyacrylamide hydrogels soaked in simulated body fluid (SBF1x). Hydrogels were prepared by polymerization of acrylamide and N,N′-methylenebisacrylamide in silk fibroin solution with a redox pair as initiator. The incorporation of the fibroin within the polyacrylamide matrix was proved by FTIR–ATR spectroscopy. Swelling measurements in saline solution were performed to evaluate the behavior of these hydrogels having various compositions. Mineralization assays in SBF1x solution revealed the presence of apatite-like crystals onto the surface of the silk fibroin/polyacrylamide hydrogels. Cytotoxicity test by extract method revealed that these hydrogels with various contents in silk fibroin have not developed cytotoxic effects on human fibroblast cultures which increases the possibility of their use in biomedical applications. Mechanical compressive tests revealed good strengths for silk fibroin/polyacrylamide hydrogels. In this way, organic–inorganic hybrids analogous to bone structure can be produced under biomimetic conditions and could be further used in biomedical applications. 相似文献
15.
A dense and pure hydroxyapatite [HA, Ca10(PO4)6(OH)2] coating and a fluoridated HA [Ca10(PO4)6(OH)0.67F1.33] are deposited on Ti6Al4V substrates by sol-gel dip coating method. Glucose and bovine serum albumin have been added in standard simulated body fluid (SBF) to form organic-containing SBF in simulation of the physiological blood plasma. The HA and the fluoridated HA coatings are immersed in the standard and modified SBF for time periods of 2, 4, 7, 14 and 28 days at 37 ± 0.1°C. After soaking, the coating surface is examined for nucleation and growth of apatite using SEM morphological observation. The post-soaking SBF solutions are analyzed via Inductively Coupled Plasma spectroscopy for calcium ion concentration. The results show that at concentration of 40 g/L, bovine serum albumin has significant retardation effect on apatite precipitation from SBF onto pure or fluoridated HA coatings; Fluorine-incorporation in HA has positive bio-activation effect in both standard SBF and organic-containing SBF. However, glucose addition in SBF does not generate significant influence on the bioactivity of HA and fluoridated HA. 相似文献
16.
Feng Lin Yucheng Li Jun Jin Yurong Cai Kemin Wei Juming Yao 《Materials Chemistry and Physics》2008,111(1):92-97
Porous 3D silk fibroin (SF) scaffolds were prepared directly from the SF solution with the addition of methanol and glutaraldehyde by a freeze-drying method. The scaffolds were then soaked in the simulated body fluid (SBF) for the deposition of hydroxyapatite (HA) crystals. The XRD and FTIR results showed that the SF were in β-sheet structure, resulting in the high thermal stability and mechanical properties of scaffolds. The XRD and AAS data revealed that the SF scaffolds could induce the continuous growth and enrichment of HA crystals onto the scaffolds with the extension of soaking time. The mechanical properties of scaffolds increased first with the HA-deposition within 3 d of soaking, then it declined. During the full soaking period, no significant change was observed on the porosity and water-binding ability, which were kept at about 84% and 800%, respectively. The cell cultivation results showed that the scaffolds have the satisfied cell biocompatibility, which was promoted after the HA-deposition. This work suggests that the porous 3D SF scaffolds may be a potential candidate in the bone engineering. 相似文献
17.
Dicalcium phosphate dihydrate (DCPD) coating was deposited on the substrate surface of magnesium alloy with solution treatment. The microstructures and corrosion behaviors of the DCPD-coated samples before and after immersion in simulated body fluid (SBF) for different times were investigated. It is important to note that DCPD was not only transformed into hydroxyapatite (HA) but also induced HA precipitation after immersion in SBF. An HA-like coating was generated on the substrate surface in a two step process involving an initial coating with DCPD, resulting in the corrosion resistance increasing along with the corrosion mechanism changing with increase to soaking time. 相似文献
18.
Ill Yong Kim Ryota Iwatsuki Koichi Kikuta Yumi Morita Toshiki Miyazaki Chikara Ohtsuki 《Materials science & engineering. C, Materials for biological applications》2011,31(7):1472-1476
Osteoconductive materials with self-setting ability have received much attention because their properties allow developing injectable materials for bone defects. Thermosensitive hydrogel with ability of bone-like apatite formation in a body environment is a candidate of injectable bone fillers with osteoconductivity because the apatite formation on materials is an essential to show osteoconduction. The present study focused on the development of a thermosensitive hydrogel through modifications of the sulphonic groups of the polysaccharide, κ-carrageenan, with potassium chloride (KCl) and calcium chloride (CaCl2). We found that the gelation temperature of κ-carrageenan solutions increased with increasing amounts of K+ ions. Apatite formation was observed on the gel after exposure to simulated body fluid for 0.5 day when the gel was prepared with a molar ratio of Ca2+/sulfonic groups = 1.5. These results indicate that a thermosensitive κ-carrageenan hydrogel with apatite-forming ability was obtained through the incorporation of K+ and Ca2+ ions into the solution. 相似文献
19.