Formation mechanism of calcium phosphate coating on micro-arc oxidized magnesium

Liu, G.Y.; Hu, Jin; Ding, Zhao-Ying; Wang, C.

doi:10.1016/j.matchemphys.2011.08.043

Cited by 38 publications

(10 citation statements)

References 27 publications

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“…Magnesium (Mg) and its alloys are classified as biodegradable materials and are promising for medical implant engineering due to their biocompatibility, non-toxicity, mechanical properties and biodegradation behavior [6][7][8][9]. The Mg elastic modulus (45 GPa) close to elastic modulus of human bone (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) allows to minimize the stress shielding [3,10,11]. Due to sufficient biomechanical properties and biodegradation ability, the Mg alloys are very perspective as materials for cardiovascular stents.…”

Section: Introductionmentioning

confidence: 99%

“…Several techniques for biocoatings deposition have been investigated to improve the corrosion resistance of Mg and its alloys, such as micro-arc oxidation (MAO), electrochemical deposition, sol-gel, hydrothermal deposition, plasma spraying, RF-magnetron sputtering, etc. The MAO, also called plasma electrolytic oxidation (PEO) or plasma-chemical oxidation (PCO), is the most technologically advanced method that allows to form on the Mg and its alloys the bioactive calcium phosphate (CaP) coatings with a wide range of physical and chemical properties, different crystallinity, thickness of hundreds micrometers, roughness and porosity [24][25][26][27][28][29][30][31]. The MAO method allows controlling and varying the coating properties, structure and composition by changing electrical parameters of the process (voltage, current density, etc.…”

Section: Introductionmentioning

confidence: 99%

“…), the electrolyte composition, and type of the substrate material (Ti, Nb, Zr, Mg, etc.) [24,25,28,[32][33][34]. Generally, the researchers have implemented the MAO processing of valve metals in electrolytic true solutions for production of biocoatings.…”

Section: Introductionmentioning

confidence: 99%

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Characterization of the Micro-Arc Coatings Containing β-Tricalcium Phosphate Particles on Mg-0.8Ca Alloy

Sedelnikova

Комарова

Sharkeev

et al. 2018

Metals

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The characterization of the microstructure, morphology, topography, composition, and physical and chemical properties of the coatings containing β-tricalcium phosphate (β-TCP) particles deposited by the micro-arc oxidation (MAO) method on biodegradable Mg-0.8Ca alloy has been performed. The electrolyte for the MAO process included the following components: Na 2 HPO 4 •12H 2 O, NaOH, NaF, and β-Ca 3 (PO 4) 2 (β-TCP). The coating morphology, microstructure, and compositions have been studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). With increasing of the MAO voltage from 350 to 500 V, the coating thickness and surface average roughness of the coatings increased linearly from 6 to 150 µm and from 2 to 8 µm, respectively. The coating deposited at 350 V had more homogeneous porous morphology with numerous pores similar by sizes (2-3 µm) than the coatings formed at 450-500 V. The β-TCP isometric particles were included in the coating surface. The XRD recognized the amorphous-crystalline structure in the coatings with incorporation of the following phases: β-TCP, α-TCP, MgO (periclase) and hydroxyapatite (HA). The corrosion experiments showed that the biodegradation rate of the Mg-0.8Ca alloy coated by calcium phosphates is almost 10 times less than that of uncoated alloy.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Characterization of the Micro-Arc Coatings Containing β-Tricalcium Phosphate Particles on Mg-0.8Ca Alloy

Sedelnikova

Комарова

Sharkeev

et al. 2018

Metals

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“…The initial formation of HA on the substrate surface has been confirmed, followed by the precipitation of DCPD flakes. 50 In Fig. 3b, the oxide layer was approximately 10 μm in thickness.…”

Section: Resultsmentioning

confidence: 96%

Corrosion Behavior of Micro-Arc Oxidized Magnesium with Calcium Phosphate Coating in Flowing Simulated Body Fluids

Tang

Zhang

et al. 2015

J. Electrochem. Soc.

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A micro-arc oxide (MAO) layer and calcium phosphate (Ca-P) coating were prepared on magnesium using a micro-oxidation technique and chemical deposition. The corrosion behavior of the MAO magnesium with and without a Ca-P coating in static and flowing simulated body fluids (SBF) was studied by electrochemical polarization and impedance spectroscopy. The microstructure of the coating was examined by scanning electron microscopy, X-ray diffraction and infrared spectroscopy. The results indicated that the micro-arc oxide layer was easily broken by the SBF, which breached the oxide layer and corroded the underlying magnesium. Solution flow promoted the failure of the oxide layer and the process of MAO magnesium corrosion. The prepared Ca-P coating consisted of hydroxyapatite (HA) and dicalcium phosphate dihydrate (DCPD). Although the Ca-P coating itself exhibited low resistance to corrosion, it effectively protected the oxide layer against failure, which then inhibited the corrosion of the Ca-P coated MAO in SBF. The presence of the Ca-P coating weakened the effect of flow on the corrosion of the coated MAO. Moreover, the Ca-P coating transformed into a thick apatite layer even in flowing SBF, which further improved the protection of the MAO magnesium.Magnesium and its alloys have received an ever-increasing amount of attention as biodegradable orthopedic implants. 1-8 Mg 2+ is one of the most abundant cations in the human body, playing an important role in human metabolism. 9 The biodegradable magnesium plates can be used to support injured bones and promote bone healing. [10][11][12] It is interesting that the use of magnesium implants could relieve the patient from secondary operations and diminish cost. 13,14 Moreover, magnesium alloy cardiovascular stents are also expected to be a desirable choice for long-term implants. 15,16 However, the rapid corrosion of magnesium in physiological media, causing too much hydrogen gas and OH − , inhibits its clinical application. 17,18 Alloying and surface treatments are commonly adopted to decrease the corrosion rate of magnesium. [19][20][21][22][23] Calcium phosphate (Ca-P) coatings have been widely studied as a barrier to the corrosion of magnesium alloys in vitro. 24-26 Various techniques of preparing Ca-P coating on the surface of magnesium alloys have been proposed, and previous studies have demonstrated that the corrosion rates of the coated magnesium alloys were strongly reduced. 27-29 Ca-P coatings have been found to increase in thickness and density during in vitro immersion, which further improved the corrosion performance of magnesium alloys. 30 Moreover, Ca-P coatings have been reported to enhance cellular adhesion, proliferation and differentiation to promote bone regeneration. 31 Xu et al. found that a Ca-P coating promoted the surface bioactivity of Mg-Mn-Zn alloy. 32 The presence of hydroxyapatite (HA) on a Mg-Zn alloy was reported to improve the bioactivity and mineralization ability of the magnesium alloy. 33 Cell culture results have also indicated that ca...

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“…The electrochemical deposition (ED) technique could fabricate a uniform coating on a porous substrate or one with a complex shape and adjust the morphology and compositions of Ca-P coating easily (10). However, single FHA coating obtained through electrochemical deposition has a low bonding strength (about 4-6 MPa), which may lead to peeling off after implantation (11,12) .…”

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confidence: 99%

Surface Modification of Mg-3Zn-0.8Ca Alloy Using Dual Micro-arc Oxidation (MAO) and Fluoridated Hydroxyapatite (FHA) Coatings

2014

Egypt. J. Chem.

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Formation mechanism of calcium phosphate coating on micro-arc oxidized magnesium

Cited by 38 publications

References 27 publications

Characterization of the Micro-Arc Coatings Containing β-Tricalcium Phosphate Particles on Mg-0.8Ca Alloy

Characterization of the Micro-Arc Coatings Containing β-Tricalcium Phosphate Particles on Mg-0.8Ca Alloy

Corrosion Behavior of Micro-Arc Oxidized Magnesium with Calcium Phosphate Coating in Flowing Simulated Body Fluids

Surface Modification of Mg-3Zn-0.8Ca Alloy Using Dual Micro-arc Oxidation (MAO) and Fluoridated Hydroxyapatite (FHA) Coatings

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