Electrophoretic Deposition of Hydroxyapatite Coatings on AZ31: The Effect of Nanoparticle Multiple Coating Approach

2015 ◽  
Vol 1125 ◽  
pp. 484-488 ◽  
Author(s):  
C.Y. Chong ◽  
Tuty Asma Abu Bakar ◽  
Nor Akmal Fadil ◽  
Rafaqat Hussain
Keyword(s):  
Electrophoretic Deposition ◽  
Coating Layer ◽  
Az31 Alloy ◽  
Amorphous Structure ◽  
The Body ◽  
X Ray Diffraction ◽  
Coating Structure ◽  
Biodegradable Implant ◽  
Hydroxyapatite Coatings ◽  
Multiple Coating

Magnesium and its alloys are potential biodegradable implant materials. However, they are characterized by rapid degradation in the electrolytic environment of the body. This phenomenon might result a sudden implant failure before bone restoration was complete, or inflammation subsided. This research will explore ways to improve the corrosion resistance of AZ31 magnesium alloy by improving the coating layer of hydroxyapatite (HA) through multiple coating layers by an electrophoretic deposition (EPD) process. In this study, the quality of the coating layer was improved by multiple coating processes without using any binders. X-ray diffraction spectrometer (XRD) showed that an amorphous structure of HA was successfully deposited on the AZ31 alloy. Scanning electron microscopy (SEM) has been used to observe that the morphology of the AZ31 alloy coated with multiple layers of HA has a denser coating structure with improved adhesion at the interface as compared to the single coating layer. A denser coating structure with greater bonding between the coating layer and the substrate is expected to protect the substrate from a high corrosion rate, thus resulting in a longer period of biodegradation as in implant in the electrolytic environment.

scholarly journals Controlling the Degradation Rate of Biodegradable Mg–Zn-Mn Alloys for Orthopedic Applications by Electrophoretic Deposition of Hydroxyapatite Coating

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 263 ◽  
Author(s):  
Iulian Antoniac ◽  
Florin Miculescu ◽  
Cosmin Cotrut ◽  
Anton Ficai ◽  
Julietta V. Rau ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Electrophoretic Deposition ◽  
Strength Properties ◽  
The Body ◽  
X Ray Diffraction ◽  
Biodegradation Rate ◽  
Simulated Environments ◽  
Before And After ◽  
Good Biocompatibility ◽  
Orthopedic Applications

Magnesium alloys as bioresorbable materials with good biocompatibility have raised a growing interest in the past years in temporary implant manufacturing, as they offer a steady resorption rate and optimal healing in the body. Magnesium exhibits tensile strength properties similar to those of natural bone, which determines its application in load-bearing mechanical medical devices. In this paper, we investigated the biodegradation rate of Mg-Zn-Mn biodegradable alloys (ZMX410 and ZM21) before and after coating them with hydroxyapatite (HAP) via the electrophoretic deposition method. The experimental samples were subjected to corrosion tests to observe the effect of HAP deposition on corrosion resistance and, implicitly, the rate of biodegradation of these in simulated environments. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) provided detailed information on the quality, structure, and morphology of the HAP coating. The obtained results demonstrate that coating of Mg-Zn-Mn alloys by HAP led to the improvement of corrosion resistance in simulated environments, and that the HAP coating could be used in order to control the biodegradation rate.

Devitrification products of rapidly solidified Ni-Nb amorphous alloys.

1990 ◽  
Vol 48 (4) ◽  
pp. 950-951
Author(s):  
G. A. Bertero ◽  
W.H. Hofmeister ◽  
N.D. Evans ◽  
J.E. Wittig ◽  
R.J. Bayuzick
Keyword(s):  
Electron Microscopy ◽  
Amorphous Structure ◽  
Sulphuric Acid Solution ◽  
X Ray Diffraction ◽  
High Fracture ◽  
Transmission Electron ◽  
Xrd Techniques ◽  
Rapidly Solidified ◽  
Electromagnetically Levitated

Rapid solidification of Ni-Nb alloys promotes the formation of amorphous structure. Preliminary results indicate promising elastic properties and high fracture strength for the metallic glass. Knowledge of the thermal stability of the amorphus alloy and the changes in properties with temperature is therefore of prime importance. In this work rapidly solidified Ni-Nb alloys were analyzed with transmission electron microscopy (TEM) during in-situ heating experiments and after isothermal annealing of bulk samples. Differential thermal analysis (DTA), scanning electron microscopy (SEM) and x-ray diffraction (XRD) techniques were also used to characterize both the solidification and devitrification sequences.Samples of Ni-44 at.% Nb were electromagnetically levitated, melted, and rapidly solidified by splatquenching between two copper chill plates. The resulting samples were 100 to 200 μm thick discs of 2 to 3 cm diameter. TEM specimens were either ion-milled or alternatively electropolished in a methanol-10% sulphuric acid solution at 20 V and −40°C.

scholarly journals Novel Hydrogels of Chitosan and Poly (vinyl alcohol) Reinforced with Inorganic Particles of Bioactive Glass

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 691
Author(s):  
O. Sánchez-Aguinagalde ◽  
Ainhoa Lejardi ◽  
Emilio Meaurio ◽  
Rebeca Hernández ◽  
Carmen Mijangos ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Drug Release ◽  
Bioactive Glass ◽  
Vinyl Alcohol ◽  
Release Kinetics ◽  
The Body ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
Inorganic Particles ◽  
Release Studies

Chitosan (CS) and poly (vinyl alcohol) (PVA) hydrogels, a polymeric system that shows a broad potential in biomedical applications, were developed. Despite the advantages they present, their mechanical properties are insufficient to support the loads that appear on the body. Thus, it was proposed to reinforce these gels with inorganic glass particles (BG) in order to improve mechanical properties and bioactivity and to see how this reinforcement affects levofloxacin drug release kinetics. Scanning electron microscopy (SEM), X-ray diffraction (XRD), swelling tests, rheology and drug release studies characterized the resulting hydrogels. The experimental results verified the bioactivity of these gels, showed an improvement of the mechanical properties and proved that the added bioactive glass does affect the release kinetics.

scholarly journals A Study of Thin Film Resistors Prepared Using Ni-Cr-Si-Al-Ta High Entropy Alloy

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Ruei-Cheng Lin ◽  
Tai-Kuang Lee ◽  
Der-Ho Wu ◽  
Ying-Chieh Lee
Keyword(s):  
Annealing Temperature ◽  
Phase Evolution ◽  
Amorphous Structure ◽  
High Entropy Alloy ◽  
X Ray Diffraction ◽  
Temperature Coefficient Of Resistance ◽  
X Ray ◽  
High Entropy ◽  
Transmission Electron ◽  
Thin Film Resistors

Ni-Cr-Si-Al-Ta resistive thin films were prepared on glass and Al2O3substrates by DC magnetron cosputtering from targets of Ni0.35-Cr0.25-Si0.2-Al0.2casting alloy and Ta metal. Electrical properties and microstructures of Ni-Cr-Si-Al-Ta films under different sputtering powers and annealing temperatures were investigated. The phase evolution, microstructure, and composition of Ni-Cr-Si-Al-Ta films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Auger electron spectroscopy (AES). When the annealing temperature was set to 300°C, the Ni-Cr-Si-Al-Ta films with an amorphous structure were observed. When the annealing temperature was at 500°C, the Ni-Cr-Si-Al-Ta films crystallized into Al0.9Ni4.22, Cr2Ta, and Ta5Si3phases. The Ni-Cr-Si-Al-Ta films deposited at 100 W and annealed at 300°C which exhibited the higher resistivity 2215 μΩ-cm with −10 ppm/°C of temperature coefficient of resistance (TCR).

scholarly journals Structural, Superconducting and Magnetic Properties of La3-XRxNi2B2N3-δ with R = Ce, Pr, Nd

2011 ◽  
Vol 170 ◽  
pp. 165-169 ◽  
Author(s):  
Tahir Ali ◽  
Ernst Bauer ◽  
Gerfried Hilscher ◽  
Herwig Michor
Keyword(s):  
Magnetic Properties ◽  
Structure Type ◽  
The Body ◽  
Spin Reorientation ◽  
Superconducting Transition ◽  
X Ray Diffraction ◽  
Range Magnetic Order ◽  
Long Range Magnetic Order ◽  
First Time ◽  
Magnetic Pair

We report on structural and superconducting properties of La3-xRxNi2B2N3- where La is substituted by the magnetic rare-earth elements Ce, Pr, Nd. The compounds Pr3Ni2B2N3- and Nd3Ni2B2N3- are characterized for the first time. Powder X-ray diffraction confirmed all samples R3Ni2B2N3- with R = La, Ce, Pr, Nd and their solid solutions to crystallize in the body centered tetragonal La3Ni2B2N3 structure type. Superconducting and magnetic properties of La3-xRxNi2B2N3- were studied by resistivity, specific heat and susceptibility measurements. While La3Ni2B2N3- has a superconducting transition temperature Tc ~ 14 K, substitution of La by Ce, Pr, and Nd leads to magnetic pair breaking and, thus, to a gradual suppression of superconductivity. Pr3Ni2B2N3- exibits no long range magnetic order down to 2 K, Nd3Ni2B2N3- shows ferrimagnetic ordering below TC =17 K and a spin reorientation transition to a nearly antiferromagnetic state at 10 K.

Preparation and Characterisation of TiO2 Thick Films Fabricated by Electrophoretic Deposition

2007 ◽  
Vol 561-565 ◽  
pp. 2163-2166 ◽  
Author(s):  
H.Z. Abdullah ◽  
Charles C. Sorrell
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Grain Growth ◽  
Electrophoretic Deposition ◽  
Defect Formation ◽  
Titanium Foil ◽  
X Ray Diffraction ◽  
Voltage Range ◽  
X Ray ◽  
Scanning Electron

Rutile nano-powders were suspended in a solution of acetylacetone and iodine. The suspensions were electrophoretically deposited on titanium foil at a voltage range of 5-30 V over times of 5-120 s. The dried tapes then were sintered at 800°C for 2 h in flowing argon. Both the green and fired tapes were examined by field emission scanning electron microscopy, optical microscopy, X-ray diffraction, and Raman microspectroscopy. The thickness of the films depended on the voltage and the time of deposition. The sintered microstructures depended significantly on the thickness of the film, which was a function the proximity to the Ti/TiO2 interface. The interface is critical to the microstructure because it acts as the source of defect formation, which enhances sintering, grain growth, and grain facetting.

Structure and Electrochemical Behavior of Plasma-Sprayed LSGM Electrolyte Films

2002 ◽  
Vol 756 ◽  
Author(s):  
H. Zhang ◽  
X. Ma ◽  
J. Dai ◽  
S. Hui ◽  
J. Roth ◽  
...  
Keyword(s):  
Electrochemical Behavior ◽  
Electrochemical Impedance ◽  
Amorphous Structure ◽  
Solid Oxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spray Process ◽  
Plasma Spray Process ◽  
Electrolyte Film ◽  
Plasma Sprayed

ABSTRACTAn intermediate temperature solid oxide fuel cell (SOFC) electrolyte film of La0.8Sr 0.2Ga0.8Mg0.2O2.8 (LSGM) was fabricated using a plasma spray process. The microstructure and phase were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical behavior of the thermal sprayed LSGM film was investigated using electrochemical impedance spectroscopy (EIS). The study indicates that thermal spray can deposit a dense LSGM layer. It was found that the rapid cooling in the thermal process led to an amorphous or poor crystalline LSGM deposited layer. This amorphous structure has a significant effect on the performance of the cell. Crystallization of the deposited LSGM layer was observed during annealing between 500–600 °C. After annealing at 800 °C, the ionic conductivity of the sprayed LSGM layer can reach the same level as that of the sintered LSGM.

Design of Alumina/Alumina Laminate Composites with Crystalline-Orientated Layers Produced by Electrophoretic Deposition under a High Magnetic Field

2006 ◽  
Vol 314 ◽  
pp. 25-32
Author(s):  
Tetsuo Uchikoshi ◽  
Tohru Suzuki ◽  
Hideo Okuyama ◽  
Yoshio Sakka
Keyword(s):  
Magnetic Field ◽  
Electrophoretic Deposition ◽  
Orientation Angle ◽  
Layer By Layer ◽  
Alumina Ceramics ◽  
X Ray Diffraction ◽  
Laminate Composites ◽  
Laminar Composites ◽  
The Magnetic Field ◽  
Oriented Layers

Highly crystalline-textured alumina ceramics were fabricated by electrophoretic deposition (EPD) in a strong magnetic field of 12 T. Preferred orientation of the bulk was controlled by changing the direction of the applied electric field E relative to the magnetic field B during the EPD. Average orientation angle of the prepared monoliths as a function of the angle between the vectors E and B, ϕ B-E was estimated from the X-ray diffraction analysis. Alumina/alumina laminar composites with crystalline- oriented layers were also fabricated by alternately changing the ϕ B-E layer by layer during EPD in a magnetic field of 12 T.

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