Controlling the degradation rate of AZ91 magnesium alloy via sol–gel derived nanostructured hydroxyapatite coating

Rojaee, Ramin; Fathi, Mohammadhossein; Raeissi, K.

doi:10.1016/j.msec.2013.05.014

Cited by 135 publications

(61 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Although plenty of coating methods such as electrodeposition [152], sol-gel and dipping [153], chemical conversion [154], anodization [155], vapor deposition [156], spin [157], and alkali treatment [158] have been proposed to inhibit rapid corrosion of Mg and its alloys, just few of them are effective and flexible enough for the formation of a uniform coating with desired thickness on the non-flat surfaces such as wires. Simultaneously, the adhesion between the substrate and the coating film is another concern that should be considered.…”

Section: Magnesiummentioning

confidence: 99%

Biodegradable Metallic Wires in Dental and Orthopedic Applications: A Review

Asgari

Hang

Chang

et al. 2018

Metals

View full text Add to dashboard Cite

Abstract:Owing to significant advantages of bioactivity and biodegradability, biodegradable metallic materials such as magnesium, iron, and zinc and their alloys have been widely studied over recent years. Metallic wires with superior tensile strength and proper ductility can be fabricated by a traditional metalworking process (drawing). Drawn biodegradable metallic wires are popular biodegradable materials, which are promising in different clinical applications such as orthopedic fixation, surgical staples, cardiovascular stents, and aneurysm occlusion. This paper presents recent advances associated with the application of biodegradable metallic wires used in dental and orthopedic fields. Furthermore, the effects of some parameters such as the surface modification, alloying elements, and fabrication process affecting the degradation rate as well as biocompatibility, bioactivity, and mechanical stability are reviewed in the most recent works pertaining to these materials. Finally, possible pathways for future studies regarding the production of more efficient biodegradable metallic wires in the regeneration of bone defects are also proposed.

show abstract

Section: Magnesiummentioning

confidence: 99%

Biodegradable Metallic Wires in Dental and Orthopedic Applications: A Review

Asgari

Hang

Chang

et al. 2018

Metals

View full text Add to dashboard Cite

show abstract

“…Alternatively, the coated specimen is placed in an air oven and held there at 150 o C for 10 min, and then, sintered at 300-900 o C [30]. On die-cast AZ91 specimens, the coating 1) has a thickness of 6.3 ± 1.1 µm [29]; 2) has poor crystallinity (index = 45%) [29], which was attributed to the low curing temperature that was used (400 o C) so as to not adversely affect the surface integrity of the substrate and decrease its tendency to react with oxygen [47,48]; and 3) is practically crack-free, homogenous, free of any delamination and/or gaps, and relatively smooth [27,29]. The last-mentioned characteristic indicates that some aspects of the performance of the coated specimen may be sub-optimal, as evidenced by low stimulation of the adhesion, growth, and proliferation of osteoblasts and low osseointegration of the coated specimens [44,45].…”

Section: Sol-gel Depositionmentioning

confidence: 99%

“…Results of an adhesion test (per ASTM D454-02) performed using a commercially-available adhesion tester found that the bonding strength of the coating to a die-cast AZ91 substrate was 4.2 ± 0.3 MPa and that there were cohesive and adhesive modes in the failure surface of the coating [29].…”

Section: Sol-gel Depositionmentioning

confidence: 99%

“…There are two focal aspects in the second section, Coating Deposition and Characterization Methods. The first involves steps used in and key process variables of each of the popular deposition methods, such as electrophoretic deposition [15,17,18,[23][24][25][26][27][28] and sol-gel [29,30]; the less popular deposition methods, such as aerosol deposition [31] and radiofrequency magnetron sputtering [32]; and proprietary deposition methods, such as a patented "transonic particle acceleration deposition process" [1]. The second focal aspect involves expositions on the influence of process variables on a large collection of properties of the coating and of the coating-bioalloy substrate system, for a given coating deposition method.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Nanostructured Hydroxyapatite Coating on Bioalloy Substrates: Current Status and Future Directions

Lewis¹

2017

JAN

View full text Add to dashboard Cite

Abstract. Several shortcomings of the alloys that are used to fabricate a number of currentgeneration biomedical implants, such as Ti-6Al-4V alloy for the femoral stem of a total hip replacement and AZ3 Mg alloy for the scaffold of a fully bioabsorbable coronary artery stent, are well-known. Examples of these shortcomings are limited bioactivity/osseointegration (in the case of Ti-based alloys) and high corrosion rate (in the case of Mg-based alloys). It is now recognized that a nanostructured hydroxyapatite (nanoHA) coating on the substrate of a bioalloy can increase bioactivity and reduce corrosion of the substrate. A large number of nanoHA deposition methods and a variety of characterization techniques/methods have been used to obtain an assortment of properties of the coating, the coated specimens, and the coating-substrate interface. Examples of these deposition methods are electrophoretic deposition and radiofrequency magnetron sputtering and some of the most frequently used characterization techniques/methods are x-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, atomic force microscopy, immersion tests in a biosimulating solution at 37 o C, and culturing in cells extracted from humans. Among the properties obtained are the morphology, thickness, size of the nanoHA; degree of crystallinity of the coating; and the adhesive strength and corrosion rate in an aqueous biosimulating solution at 37 o C. The present work is a comprehensive review of the very large body of literature in this field, with the focal topics being essential steps in a deposition method, discussion of the influence of deposition method variables on myriad coating properties (for a given deposition method), and identification of the shortcomings of the literature, and, hence, outlines of ten suggested directions for future research.

show abstract

“…HA coatings are degradable in physiological environment and show good early interaction between the implant and the tissue [35]. Much research has been done on the fabrication of HA coatings on magnesium and its alloys; preparation methods include electrodeposition [36][37][38], aerosol deposition [39], chemical solution deposition [40], sol-gel method [41], and other processes [42,43]. It should be pointed that the poor bonding strength, corrosion resistance, and inhomogeneity of simplex HA coatings still restrict their application.…”

Section: Introductionmentioning

confidence: 99%

Bio-Corrosion Behavior of Ceramic Coatings Containing Hydroxyapatite on Mg-Zn-Ca Magnesium Alloy

Ding

Wang

et al. 2018

Applied Sciences

View full text Add to dashboard Cite

Ceramic coatings containing hydroxyapatite (HA) were fabricated on a biodegradable Mg 66 Zn 29 Ca 5 magnesium alloy through micro-arc oxidation by adding HA particles into the electrolytes. The phase composition and surface morphology of the coatings were characterized by X-ray diffraction and scanning electron microscopy analyses, respectively. Electrochemical experiments and immersion tests were performed in Hank's solution at 37 • C to measure the corrosion resistance of the coatings. Blood compatibility was evaluated by in vitro blood platelet adhesion tests and static water contact angle measurement. The results show that the typical ceramic coatings with a porous structure were prepared on the magnesium alloy surface with the main phases of MgO and MgSiO 3 and a small amount of Mg 3 (PO 4 ) 2 and HA. The optimal surface morphology appeared at HA concentration of 0.4 g/L. The electrochemical experiments and immersion tests reveal a significant improvement in the corrosion resistance of the ceramic coatings containing HA compared with the coatings without HA or bare Mg 66 Zn 29 Ca 5 magnesium alloy. The static water contact angle of the HA-containing ceramic coatings is 18.7 • , which is lower than that of the coatings without HA (40.1 • ). The in vitro blood platelet adhesion tests indicate that the HA-containing ceramic coatings possess improved blood compatibility compared with the coatings without HA. Utilizing HA-containing ceramic coatings may be an effective way to improve the surface biocompatibility and corrosion resistance of magnesium alloys.

show abstract

Controlling the degradation rate of AZ91 magnesium alloy via sol–gel derived nanostructured hydroxyapatite coating

Cited by 135 publications

References 42 publications

Biodegradable Metallic Wires in Dental and Orthopedic Applications: A Review

Biodegradable Metallic Wires in Dental and Orthopedic Applications: A Review

Nanostructured Hydroxyapatite Coating on Bioalloy Substrates: Current Status and Future Directions

Bio-Corrosion Behavior of Ceramic Coatings Containing Hydroxyapatite on Mg-Zn-Ca Magnesium Alloy

Contact Info

Product

Resources

About