scholarly journals Effect of Grinding and Resintering on the Fatigue Limit and Surface Characterization of a Y-TZP Ceramic

2016 ◽  
Vol 27 (4) ◽  
pp. 468-475 ◽  
Author(s):  
Gabriela Scatimburgo Polli ◽  
Gabriel Rodrigues Hatanaka ◽  
Filipe de Oliveira Abi-Rached ◽  
Lígia Antunes Pereira Pinelli ◽  
Márcio de Sousa Góes ◽  
...  
Keyword(s):  
Fatigue Limit ◽  
Surface Characterization ◽  
Monoclinic Phase ◽  
The Other ◽  
X Ray Diffraction ◽  
Staircase Method ◽  
X Ray ◽  
Significant Difference ◽  
Fracture Area

Abstract This study evaluated the effect of grinding protocols and resintering on flexural fatigue limit and surface characterization of LavaTM Y-TZP. Bar-shaped specimens (20×4.0×1.2 mm, n=40; 20×4.0×1.5 mm, n=80) were obtained. Half of the thinner specimens (1.2 mm) constituted the as-sintered group (AS), while the thicker ones (1.5 mm) were ground with diamond burs under irrigation (WG) or not (G). The other half of thinner and half of ground specimens were resintered (1000 ºC, 30 min), forming the groups ASR, WGR and GR. Fatigue limit (500,000 cycles, 10 Hz) was evaluated by staircase method in a 4-point flexural fixture. Data were analyzed by 2-way ANOVA and Tukey's test (α=0.05). Surface topography (n=3) and fracture area (n=3) were evaluated by SEM. X-ray diffraction data (n=1) was analyzed by Rietveld refinement. ANOVA revealed significant differences (p<0.001) for the grinding protocol, resintering and their interaction. Grinding increased the fatigue limit of non-resintered groups. There was no significant difference among the resintered groups. Resintering significantly increased the fatigue limit of the AS group only. Both protocols created evident grooves on zirconia surface. The failures initiated at the tensile side of all specimens. The percentages (wt%) of monoclinic phase were AS (8.6), ASR (1.2), G (1.8), GR (0.0), WG (8.2), WGR (0.0) before, and AS (7.4), ASR (6.5), G (3.2), GR (0.2), WG (4.6), WGR (1.1) after cyclic loading. Grinding increased the fatigue limit of non-resintered Y-TZP and formed evident grooves on its surface. Resintering provided significant increase in the fatigue limit of as-sintered specimens. In general, grinding and resintering decreased or zeroed the monoclinic phase.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Preparation and Application of Lead Dioxide Electrode for Zinc Electrolysis

2013 ◽  
Vol 785-786 ◽  
pp. 1125-1129
Author(s):  
Xiao Yong Yang ◽  
Pei Xian Zhu ◽  
Yun Sen Si
Keyword(s):  
Surface Characterization ◽  
Catalytic Properties ◽  
Lead Dioxide ◽  
Manufacturing Cost ◽  
X Ray Diffraction ◽  
Simulation Test ◽  
X Ray ◽  
Zinc Smelter ◽  
Lead Dioxide Electrode

According to the process of anodic oxygen evolution in sulfate system for zinc electrolysis,Ti-base lead dioxide electrode can be prepared to use in this case.The surface characterization of the electrode was studied by Scanning electron microscopy(SEM) and X-ray diffraction(XRD).The electrode lifetime was tested in 1mol/L H2SO4solution at 60°C,and the electro-catalytic properties was examined by polarization curves.Then these samples was enlarged and simulation test was conducted at Mengzi marriage zinc smelter in Yunnan.The results show that the electro-catalytic properties is better and the electrodes lifetime is longer compared to the traditional lead electrode.Moreover,it has a significant effect in reducing energy consumption, manufacturing cost and improving the production and grade of zinc.

scholarly journals Effects of strain on La0.67-x Prx Ca0.33 MnO3, LaMn1-x Cox O3 and LaMn1-x Nix O3 magnetite samples

DYNA ◽  
2019 ◽  
Vol 86 (211) ◽  
pp. 278-287
Author(s):  
Javier Alberto Olarte Torres ◽  
María Cristina Cifuentes Arcila ◽  
Harvey Andrés Suárez Moreno
Keyword(s):  
Compressive Strength ◽  
Magnetic Susceptibility ◽  
Sol Gel ◽  
Morphological Characterization ◽  
Electric Resistivity ◽  
The Other ◽  
X Ray Diffraction ◽  
Metal Insulator ◽  
X Ray

This paper presents the results obtained from the synthesis and morphological characterization of different magnetite samples:  La0.67-x Prx Ca0.33 MnO3.LaMn1-x Cox O3 and LaMn1-x Nix O3 at 0.13 ≤ 𝑥𝑥 ≤ 0.67 produced by a solid-state reaction mechanism and 𝐿𝐿𝐿𝐿𝑀𝑀𝑀𝑀1−𝑥𝑥(𝐶𝐶𝐶𝐶/𝑁𝑁𝑁𝑁)𝑥𝑥𝑂𝑂3 at 0.0 ≤ 𝑥𝑥 ≤ 0.5 produced by the sol-gel method. These samples were characterized using X-ray diffraction spectroscopy and by measuring electric resistivity and magnetic susceptibility which were carried out as a function of temperature. Notably, the effects of strain and compressive strength on the lattices of magnetite samples were highly dependent on the concentration of 𝑃𝑃𝑟𝑟, 𝐶𝐶𝐶𝐶, and 𝑁𝑁𝑁𝑁. Moreover, the transition temperatures of metal-insulator and ferromagnetic-paramagnetic phases also largely depend on these strength effects, e.g., at higher concentrations of 𝑃𝑃𝑟𝑟, effects of increased strain strength were observed, relocating the shifts of ferromagnetic-paramagnetic transitions to lower temperatures. On the other hand, effects of increased compressive strength were observed at higher concentrations of 𝑁𝑁𝑁𝑁 and 𝐶𝐶𝐶𝐶, relocating the shifts of ferromagnetic-paramagnetic and metal-insulator transitions to higher temperatures.

Surface Characterization of Carbon-Bearing Magnetite (CBM) and Carbon-Bearing Ni(II)-Ferrite (CBNF)

1994 ◽  
Vol 344 ◽  
Author(s):  
T. Sano ◽  
K. Akanuma ◽  
M. Tsuji ◽  
Y. Tamaura
Keyword(s):  
Photoelectron Spectroscopy ◽  
Spinel Structure ◽  
Surface Characterization ◽  
Carbon Deposition ◽  
X Ray Diffraction ◽  
Xps Spectra ◽  
X Ray ◽  
Oxygen Ions ◽  
Diffraction Patterns

AbstractOxygen-deficient magnetite (ODM; Fe3O4-δ, δ>0) synthesized by reduction of magnetite with H2 at 300°C decomposed CO2 to carbon with an efficiency of nearly 100% at 300°C. In this reaction, two oxygen ions of the CO2 were incorporated into the spinel structure of ODM and carbon was deposited on the surface of ODM with zero valence to form visible particles. The particles of carbon separated from ODM were studied by Raman, energy-dispersive X-ray and wave-dispersive X-ray spectroscopies. The carbon which had been deposited on the ODM was found to be a mixture of graphite and amorphous carbon in at least two levels of crystallization. X-ray photoelectron spectroscopy and X-ray diffraction patterns of the carbon-bearing magnetite (CBM) showed no indication of carbide (Fe3C) or metallic iron (α-Fe) phase formation. In the C 1s XPS spectra of the CBM, no peaks were observed which could be assigned to CO2 or CO. X-ray diffractometry, chemical analysis and TG-MS measurement showed that the carbon-bearing Ni(II)-ferrite (CBNF) (Ni(II)/Fetotal = 0.15) synthesized by the carbon deposition reaction from CO2 with the H2-reduced Ni(II)-ferrite was represented by (Ni0.28Fe2.72O4.00)1-δ (Ni2+06.9Fe2+2.31O3.00)δCτ (δ= 0.27, τ= 0.17). The carbon of the CBNF gave the CIOlayer-like oxide containing some Ni2+ ions.

scholarly journals New insights on the crystalline forms in binary systems of n-alkanes: Characterization of the solid ordered phases in the phase diagram tricosane + pentacosane

1999 ◽  
Vol 14 (6) ◽  
pp. 2644-2654 ◽  
Author(s):  
F. Rajabalee ◽  
V. Métivaud ◽  
D. Mondieig ◽  
Y. Haget ◽  
M. A. Cuevas-Diarte
Keyword(s):  
Phase Diagram ◽  
Binary Systems ◽  
The Other ◽  
Structural Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ordered Phases ◽  
Crystalline Forms ◽  
Mixed Samples

X-ray diffraction analyses of the pure components n-tricosane and n-pentacosane and of their binary mixed samples have enabled us to characterize the crystalline phases observed at “low temperature.” Contrary to what was announced in literature on the structural behavior of mixed samples in odd-odd binary systems with Δn = 2, the three domains are not all orthorhombic. This work has enabled us to show that two of the domains are, in fact, monoclinic (Aa, Z = 4), and the other one is orthorhombic (Pca21, Z = 4). The conclusions drawn in this work can easily be transposed to other binary systems of n-alkanes.

Characterization of Clay from Vale do Mulembá - ES

2008 ◽  
Vol 591-593 ◽  
pp. 487-492 ◽  
Author(s):  
Monica Castoldi Borlini Gadioli ◽  
J.C.G. Correia ◽  
A. Caranassios
Keyword(s):  
Particle Size ◽  
Chemical Analysis ◽  
Thermal Analyses ◽  
The Other ◽  
High Plasticity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Characterization Studies ◽  
And Behavior

This work has for objective to characterize the clay from Vale do Mulembá-ES. The Vale do Mulembá is located in Joana D´Arc, Vitória in Espírito Santo State, Brazil. That clay is used in the production of the traditional clay pans of the State, what contributes to the economy of the area. The clay from Vale do Mulembá presents characteristics and behavior different from the other clays used for the production of clay pans. The characterization studies were carried out through chemical analysis, X-ray diffraction, particle size distribution, plasticity and thermal analyses (DTA, TGA). The results showed that the clay is typical kaolinitic, present relatively to the amount high of Al2O3 and high plasticity.

Metallographic, Structural and Mechanical Characterization of a Low Density Fe-Mn-Al-C Steel Microalloyed with Ti/B in As-Cast and Homogenized Conditions

MRS Advances ◽  
2018 ◽  
Vol 3 (64) ◽  
pp. 3971-3978 ◽  
Author(s):  
O.E. Villanueva-Perez ◽  
I. Mejía ◽  
V. García-García ◽  
A. Bedolla-Jacuinde
Keyword(s):  
Grain Size ◽  
Mechanical Characterization ◽  
The Other ◽  
Low Density ◽  
X Ray Diffraction ◽  
X Ray ◽  
Other Hand ◽  
Average Grain Size ◽  
Cast Condition

ABSTRACTLow density (LD) steels have shown particular characteristics in terms of mechanical properties and microstructure, since they have high strength, high ductility and density reduction up to 18%. On the other hand, the addition of microalloying elements such as Ti and B generate hardening by solid solution and precipitation, as well as grain refinement effect. LD steels generate nano-sized kappa phase precipitated from the austenite matrix, and these advanced steels can reach strength and elongation up to 780 MPa and 60%, respectively. The main objective of this research work is the metallographic, structural and mechanical characterization of a LD steel microalloyed with Ti/B in as-cast and -homogenized conditions. For this purpose a Fe-27Mn-7Al-1.2C (%wt) LD steel microalloyed with Ti/B was melted in a vacuum-induction furnace and cast in metallic mold. LD-Ti/B steel samples were homogenized at 1100 °C during 20, 50, 100, 150 and 200 minutes followed by water quenching. Metallographic, structural and mechanical characterization was carried out by optical (LOM) and scanning electron (SEM) microscopy, X-ray diffraction (XRD) and microhardness Vickers testing (HV10), respectively. In general, results showed a typical dendritic microstructure with average grain size of 1256 μm in the as-cast condition. On the other hand, the as-homogenized condition showed an austenitic equiaxial microstructure with average grain size from 164 to 940 μm. Austenite, ferrite and kappa phases were detected by X-ray diffraction (XRD). Also, second-phase particles such as AlN, TiC and MnS were detected by LOM and SEM-EDS analysis. LD steel microalloyed with Ti/B exhibited the highest microhardness Vickers value (235 HV10) in the as-cast condition, whilst in the as-homogenized condition microhardness gradually decreases from 223 to 198 HV10 as holding time increases.

Thermal and structural characterization of the ZrO2−x(OH)2xto ZrO2 transition

2001 ◽  
Vol 16 (8) ◽  
pp. 2209-2212 ◽  
Author(s):  
E Torres-GarciÁa ◽  
A. Peláiz-Barranco ◽  
C. Vázquez-Ramos ◽  
G. A. Fuentes
Keyword(s):  
High Resolution ◽  
Metastable Phase ◽  
Nitrogen Adsorption ◽  
The Other ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
X Ray ◽  
Exothermic Process

The exothermic process that occurs around 700 K during calcination of ZrO2−x(OH)2x, associated with the crystallization of the low-temperature tetragonal metastable phase of ZrO2, was analyzed using x-ray diffraction, high-resolution thermogravimetric analysis (TGA), nitrogen adsorption, and modulated differential scanning calorimetry (MDSC). High-resolution TGA allowed us to determine the water loss, resulting from condensation of OH− groups. The amount was 0.137 wt% in our case, equivalent to 1.7 × 10−2 mol of H2O/mol of ZrO2. That corresponds to about one −OH group per nm2 being lost in that process. By using MDSC we determined that the change in enthalpy (∆Hglobal = −15.49 kJ/mol of ZrO2) was the result of two parallel contributions. One of them was reversible and endothermic (∆Hrev = 0.11 kJ/mol of ZrO2), whereas the other was irreversible and exothermic (∆Hirrev = −15.60 kJ/mol of ZrO2). The variability and magnitude of the exotherm, as well as the fact that the accompanying weight loss is so small, are consistent with a mechanism involving the formation of tetragonal nuclei, rather than global crystallization, and hence depend on the number of nuclei so formed.

Structural Characterization of a [Cl3CuL]- (L=Nitrogen Base) Species. A Novel Coordination Environment for Copper(II)

1985 ◽  
Vol 38 (5) ◽  
pp. 669 ◽  
Author(s):  
PC Healy ◽  
C Pakawatchai ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Structural Characterization ◽  
The Other ◽  
X Ray Diffraction ◽  
Nitrogen Base ◽  
Coordination Environment ◽  
X Ray

The crystal structure of [C13H10N] [CuCl3(C13H9N)].H2O(C13H9N ≡ acridine ) has been determined by single-crystal X-ray diffraction methods at 295 K, being refined by least squares to a residual of 0.037 for 1942 independent 'observed' reflections. Crystals are triclinic, Pī , a 16.27(2), b 10.080(8), c 7.236(5) Ǻ, α 88.85(6), β 82.68(8), γ 81.12(9)°, Z 2. The metal atom stereochemistry is unusual, being of pseudo-m symmetry; one of the chlorine atoms is coplanar with the copper and the acridine [Cu- Cl 2.237(2) Ǻ, N-Cu- Cl 143.5(1)°], with the other two disposed to either side of that plane [Cu- Cl 2.252(3), 2.243(2) Ǻ; Cl-Cu-Cl 145.62(7)°]. Cu-N is 2.018(5) Ǻ.

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