X-Ray Diffraction Characterization of Crystallinity and Phase Composition in Plasma-Sprayed Hydroxyapatite Coatings

2000 ◽  
Vol 9 (3) ◽  
pp. 369-376 ◽  
Author(s):  
Paul S. Prevéy
Keyword(s):  
Phase Composition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydroxyapatite Coatings ◽  
Plasma Sprayed

Synthesis and Characterization of Y2O3 Nanoflowers

2012 ◽  
Vol 465 ◽  
pp. 76-79 ◽  
Author(s):  
Shuang Zhan ◽  
Xia Li
Keyword(s):  
Fourier Transform ◽  
Phase Composition ◽  
Electron Microscope ◽  
Synthesis And Characterization ◽  
The Novel ◽  
X Ray Diffraction ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Scanning Electron

The novel Y2O3 nanoflowers were synthesized through a facile hydrothermal method without using any catalyst or template. The phase composition and the microstructure of as-prepared products were characterized by field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD) as well as Fourier transform infrared spectrum. The formation mechanism for the Y2O3 flowers has been proposed.

Influence of Sterilization with γ-Irradiation in the Degradation of Plasma Sprayed Hydroxyapatite Coatings

2006 ◽  
Vol 514-516 ◽  
pp. 1054-1058 ◽  
Author(s):  
Tânia Costa ◽  
Ana Paula Serro ◽  
Eduardo Pires ◽  
Rogerio Colaço
Keyword(s):  
Mechanical Behaviour ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
Γ Irradiation ◽  
Water Contact ◽  
X Ray ◽  
Angle Measurements ◽  
Hydroxyapatite Coatings ◽  
Plasma Sprayed ◽  
Irradiation Process

The influence of sterilization with γ-irradiation in the properties of plasma sprayed hydroxyapatite (HAp) coatings used for medical implants is investigated in this work. HAp coatings were applied on titanium alloy substrates by plasma spraying and then submitted to 1 and 10 cycles of sterilization with γ-irradiation. As-applied HAp coatings were used as control samples. Afterwards, the modifications on the samples, induced by the irradiation process, were evaluated by X-ray diffraction and X-ray photoelectron spectroscopy (XPS). Water contact angle measurements as well as adhesion tests were also carried out in order to evaluate the influence of the irradiation process on the wettability and mechanical behaviour of the HAp coatings. No microstructural modifications were detected by X-ray diffraction after sterilization. However, the results show that sterilization with γ-irradiation originates modifications of the surface of HAp, as detected by a change of color of the coatings and by the XPS analysis. Nevertheless, these modifications do not result in significant changes in the wettability and mechanical behaviour of the HAp coatings.

scholarly journals X Preparation and Characterization of Carbon-Based Composite Nanofibers for Supercapacitor

2017 ◽  
Vol 17 (2) ◽  
pp. 129-134 ◽  
Author(s):  
Dawei Gao ◽  
Lili Wang ◽  
Chunxia Wang ◽  
Yuping Chang ◽  
Pibo Ma
Keyword(s):  
Carbon Nanotubes ◽  
Phase Composition ◽  
Electron Microscope ◽  
Surface Area ◽  
Composite Nanofibers ◽  
Carbon Composite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Abstract Polyacrylonitrile (PAN)/Co(OAc)2/carbon nanotubes (CNTs) composite nanofibers were fabricated via electrospinning with N,N-dimethylformamide (DMF) as solvent, and by carbonization and activation of the above precursor nanofibers, porous carbon composite nanofibers were successfully obtained. Scanning electron microscope, X-ray diffraction, ASAP 2020, and Solartron 1470 were used to characterize the surface morphology, the phase composition, specific surface area, and electrochemical property of the nanofibers, respectively. The result showed that some of the fibers were broken after sintering, and the surface area and pore volume of the porous C/Cu/CNTs were 771 m2/g and 0.347 cm3/g, respectively. The specific capacitance of the composite nanofibers reached up to 210 F/g at the current density of 1.0 A/g. Its energy density and power density were 3.1 Wh/Kg and 2,337 W/Kg, respectively, at the current of 0.5 and 5 mA.

Effects of Spraying Parameters on Phase Formation and Distribution in Plasma-Sprayed Hydroxyapatite Coatings

2000 ◽  
Author(s):  
L. Sun ◽  
C.C. Berndt ◽  
R.S. Lima ◽  
A. Kucuk ◽  
K.A. Khor
Keyword(s):  
Opposite Effect ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
Tetracalcium Phosphate ◽  
X Ray ◽  
Impurity Phases ◽  
Hydroxyapatite Coatings ◽  
Spraying Parameters ◽  
Plasma Sprayed ◽  
Spray Dried

Abstract Calcined spray-dried hydroxyapatite (Ca10(PO4)(OH)6; i.e., HA) powders were atmospherically plasma sprayed (APS) using various process parameters. The resulting phases within the coating surface and the interface between the coating and the substrate were analyzed using X-ray diffraction (XRD) methods. This XRD revealed the presence of both amorphous (i.e., amorphous calcium phosphate: ACP) and crystalline phases. The crystalline phases included both HA and some impurity phases from the decomposition of HA, such as tricalcium phosphate (α-TCP and β-TCP), tetracalcium phosphate (TTCP) and calcium oxide (CaO). The crystallinity of HA decreased with increasing spray power and stand-off distance (SOD). The percentage of all impurity phases increased with the spray power. The percentage of both TCP and TTCP decreased with the SOD while the CaO percentage increased. In addition, the percentage of ACP and CaO were higher in the interface than at the surface of the coating while the percentage of TCP and TTCP exhibited the opposite effect.

Adhesion Characterization of Zinc-Substituted Hydroxyapatite Coatings

2016 ◽  
Vol 720 ◽  
pp. 189-192
Author(s):  
Marcelo Henrique Prado da Silva ◽  
Daniel Navarro da Rocha ◽  
Felipe Nobre Moura ◽  
Andrea Machado Costa ◽  
Luis Henrique Leme Louro
Keyword(s):  
Hydrothermal Process ◽  
Precursor Solution ◽  
Second Step ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydroxyapatite Coatings ◽  
Zn Concentration ◽  
Zn Content ◽  
Scratch Tests

In this study, hydroxyapatite and Zn-containing hydroxyapatite coatings were produced and characterized with respect to adhesion. The coating technique consists of a two-step hydrothermal process. X-ray diffraction (XRD) analyses showed that, in the first step, the coatings consisted of parascholzite (JCPDS-01-086-2372), a mixture of parascholzite and monetite (JCPDS-01-071-1759), or parascholzite and brushite (JCPDS-72-0713), depending on Zn concentration in the precursor solution. The second step consisted of an alkali conversion in a KOH solution. The final coating was identified as pure hydroxyapatite (HA) or Zn-doped hydroxyapatite, depending on the precursor solution Zn content. Scratch tests on the pure HA coatings showed higher adhesion, when compared to Zn-substituted HA coatings.

Phase Composition Changes in Annealed Plasma-Sprayed Zircon-Alumina Coatings

1997 ◽  
Author(s):  
J. Dubsky ◽  
K. Neufuss ◽  
B. Kolman
Keyword(s):  
Phase Composition ◽  
Spinel Phase ◽  
Eutectic Mixture ◽  
X Ray Diffraction ◽  
Free Standing ◽  
Amorphous Sio2 ◽  
X Ray ◽  
Water Stabilized Plasma ◽  
Plasma Sprayed ◽  
Fast Quenching

Abstract Phase transformations and/or decomposition of deposited compounds have an indisputable influence on materials properties of plasma sprayed deposits. Using water stabilized plasma, free-standing parts were manufactured from a mechanical mixture of zircon and alumina powders and annealed. The phase composition was determined by X-ray diffraction and the chemical composition was checked by x-ray microanalysis. ZrSiO4 during plasma spraying decomposes into ZrO2 and SiO2. In the as-sprayed condition, after a relatively fast quenching, the following phases can be found: a very fine eutectic mixture of tetragonal and monoclinic ZrO2, amorphous SiO2 and a spinel phase of Al2O3. On annealing for 2 hours at 1300 and 1500 °C the spinel Al2O3 transformed to corundum. At the same time, amorphous silica crystallized. Tetragonal ZrO2 transformed to the monoclinic modification and together with SiO2 formed again ZrSiO4. At the highest annealing temperature Al2O3 and SiO2 partialy reacted to form a small amount of mullite (3Al2O3.2SiO2).

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