Formation of Porous (Ca, P)-Doped TiO2/Dense Ti Double Coatings on NiTi Alloy

2011 ◽  
Vol 675-677 ◽  
pp. 333-336 ◽  
Author(s):  
Hong Zhao ◽  
Cui Cui Tian ◽  
Guo Qiang Lin ◽  
Zhen Dong Ge ◽  
Min Qi ◽  
...  

NiTi alloys are widely used for bone implants due to their good mechanical properties. However, they can suffer certain disadvantages, such as leaching of toxic nickel ions and poor osteoinductive properties. A porous (Ca, P)-doped TiO2 /dense Ti double coatings on NiTi alloy with porous (Ca, P)-doped TiO2 coating as the top layer and a dense Ti coating as the interlayer should possess a very good combination of bioactivity and chemical stability. In this paper, the double coatings were formed by applying a duplex process of arc ion plating (AIP) and micro-arc oxidation (MAO). X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron probe microanalysis (EPMA) have been used to investigate the microstructure and morphology of the coatings.

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1028 ◽  
Author(s):  
M. Mashrur Zaman ◽  
Sytle M. Antao

This study investigates the crystal chemistry of monazite (APO4, where A = Lanthanides = Ln, as well as Y, Th, U, Ca, and Pb) based on four samples from different localities using single-crystal X-ray diffraction and electron-probe microanalysis. The crystal structure of all four samples are well refined, as indicated by their refinement statistics. Relatively large unit-cell parameters (a = 6.7640(5), b = 6.9850(4), c = 6.4500(3) Å, β = 103.584(2)°, and V = 296.22(3) Å3) are obtained for a detrital monazite-Ce from Cox’s Bazar, Bangladesh. Sm-rich monazite from Gunnison County, Colorado, USA, has smaller unit-cell parameters (a = 6.7010(4), b = 6.9080(4), c = 6.4300(4) Å, β = 103.817(3)°, and V = 289.04(3) Å3). The a, b, and c unit-cell parameters vary linearly with the unit-cell volume, V. The change in the a parameter is large (0.2 Å) and is related to the type of cations occupying the A site. The average <A-O> distances vary linearly with V, whereas the average <P-O> distances are nearly constant because the PO4 group is a rigid tetrahedron.


2014 ◽  
Vol 783-786 ◽  
pp. 1426-1431
Author(s):  
Wang Ryeol Kim ◽  
Min Chul Kwon ◽  
Jung Hoon Lee ◽  
Uoo Chang Jung ◽  
Won Sub Chung

TiAlSiN coatings were deposited on WC-Co metal by using a cathodic arc ion deposition method of cylindrical cathode. We used Ti / Al (50 / 50 at.%) arc target and silicon sputter target. The influence of the nitrogen pressure, TiAl cathode arc current, bias voltage, and deposition temperature on the mechanical and the structural properties of the films were investigated. The structural features of the films were investigation in detail using X-ray diffraction. And coatings were characterized by means of FE-SEM, nanoindentation, Scratch tester, Tribology tester, XRD and XPS. The hardness of the film reached 43 GPa at the cathode arc current of 230 A and decreased with a further increase of the arc current. And the adhesion of the film reached 34 N. The results showed that the TiAlSiN coating exhibited an excellent mechanical properties which application for tools and molds.


2011 ◽  
Vol 189-193 ◽  
pp. 743-746
Author(s):  
Jian Feng Li ◽  
Li Zhi Guo ◽  
Guo Qing Li

This article summarized depositing craft of the superficial coatings (Ni-Co-Cr-Al-Y-Si) on the Ti60 alloy (Ti-6.5Al-4.2Sn-4Zr-0.6Si) with arc ion plating technology and the oxidation behavior under 600~750 . The X-ray diffraction (XRD) and the scanning electronic microscope (SEM) were used to analyze the surface appearance, the structure and the ingredient conducts of non-coating Ti60 alloy. The contrast shows that the coatings have good protection to Ti60 alloy. The result indicated that the coating has the good oxidation resistance performance under 600°C , 650°C and 750°C . Coated Ti60 alloy oxidation resistance is markly improved. The circulation oxidation dynamics curve basically conforms to the parabola rule.


2016 ◽  
Vol 5 (2) ◽  
pp. 144
Author(s):  
Doungmo Giscard ◽  
Théophile Kamgaing ◽  
Ranil Clément Tonleu Temgoua ◽  
Ervice Ymele ◽  
Francis Merlin Melataguia Tchieno ◽  
...  

In this study, sorption properties of a synthesized anionic clay were enhanced by the intercalation of oxalate ions in its interlayer space. The pristine and modified clay materials were characterized by X-ray diffraction, Fourier transform infrared spectroscopy and thermal analysis. These techniques confirmed the presence of oxalate ions in the interlayer space of the clay. The intercalated clay was then used as a matrix for the sorption in batch mode of nickel ions in aqueous solution. The influence of a number of parameters such as contact time, pH, initial concentration of the analyte and adsorbent dosage were studied. The maximum adsorption of nickel was obtained at pH 6, that is, about 90% Ni2+ removal. The adsorbent/adsorbate equilibrium follows a pseudo-second order kinetics and best matches the Langmuir model. The modified clay was shown to be efficient matrix for the sorption of nickel ions.


Author(s):  
Srimala Sreekantan ◽  
Roshasnorlyza Hazan ◽  
Zainovia Lockman ◽  
Ishak Mat

The present study is directed to clarify the influence of carbon doping on the degradation of methyl orange. TiO2 nanotubes were prepared by anodizing titanium foils in a two electrode configuration bath with titanium foil as the anode and platinum as the counter electrode. The electrochemical bathconsists of 1 M Na2SO4 with 0.7 g ammonium fluoride, NH4F. The nanotubes obtained were further doped with carbon via in-situ and ex-situ method. Incorporation of carbon on TiO2 via in-situ method is accomplished during the anodization process by introducing oxalic acid into electrolyte while theex-situ doping involves carbon incorporation into pre-fabricated TiO2 nanotube via flame annealing using carbon blackN330. Characterization such as Scanning Electron Microscope (SEM), Energy Dispersive X-ray Analysis (EDX), and X-Ray Diffraction (XRD) are used to determine the surfacemorphology, composition of dopants, and phases exists. Well ordered nanotube with good adherence and smooth surface was obtained for both methods. When the oxide was annealed, X-ray diffraction analysis revealed the presence of anatase and rutile phase. The photocatalytic properties of thepure TiO2 and carbon doped TiO2 were tested for methyl orange degradation and the result indicated that the in-situ doped TiO2 has much better degradation than the ex-situ and pure TiO2. The percentage of methyl orange degradation for in-situ was 20% and 41% higher than ex-situ doped TiO2 and pure TiO2, respectively.


1982 ◽  
Vol 46 (341) ◽  
pp. 445-448 ◽  
Author(s):  
R. R. Harding ◽  
R. J. Merriman ◽  
P. H. A. Nancarrow

AbstractThe occurrence of three accessory minerals with significant rare earth contents in Tertiary acid rocks of St. Kilda is described. Allanite, zirkelite, and chevkinite were identified by electron probe analysis (with energy-dispersive attachment) and the chevkinite confirmed by X-ray diffraction. Brief comparison is made with other Tertiary occurrences of RE minerals. This is the first recorded occurrence of chevkinite in Great Britain.


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