Characterization of ZrO2 and Al2O3 Bioceramics Obtained by Gelcasting

2008 ◽  
Vol 591-593 ◽  
pp. 482-486
Author(s):  
Claudinei dos Santos ◽  
Pedro H.B. Prado ◽  
Fernando dos Santos Ortega
Keyword(s):  
Relative Density ◽  
Tetragonal Zirconia ◽  
Advanced Materials ◽  
Solid Loading ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
X Ray ◽  
Novel Method ◽  
Near Net Shape

Gelcasting is a novel method of forming ceramics and has been increasingly employed in preparing complex-shaped, near-net-shape advanced materials. In this work, alumina, zirconia and alumina-zirconia bioceramics were shaped by gelcasting, using MAM-MBAM monomer system, with subsequent sintering and characterization. High purity tetragonal ZrO2 (3mol%Y2O3) and .Al2O3 powders were used as starting powders. Powder mixture containing 80 wt.% of alumina and 20 wt.% of tetragonal zirconia were obtained by milling/homogenization. In all cases, the suspension obtained had at least 55 vol.% solid loading. Ceramic bodies were demolded, dried and characterized by green relative density. The compacts were sintered in air at 1550 and 15750C, for 120 minutes, with controlled heating-rate to facilitate organic compounds removal. Sintered samples were characterized by relative density, and analyzed by X-Ray diffraction and scanning electronic microscopy. Hardness and fracture toughness were determined using Vicker’s indentation method.

Mechanical Behavior of the Cr3C2 Compound at High Pressure and High Temperature

2015 ◽  
Vol 1120-1121 ◽  
pp. 1187-1193 ◽  
Author(s):  
Bin Li Jiang ◽  
Zi Li Kou ◽  
De Jiang Ma ◽  
Yong Kun Wang ◽  
Chun Xia Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Pressure ◽  
Relative Density ◽  
X Ray Diffraction ◽  
Density Measurements ◽  
X Ray ◽  
Hardness Tests ◽  
Novel Method ◽  
Heat Preservation

In the present study, we present a novel method to sinter Cr3C2 powders under high pressure without any addittives. The sintering Cr3C2 samples were charaterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), relative density measurements, Vicker’s hardness tests and Fracture toughness tests. The reasults show that Cr3C2 powders could be sintered to be bulk under the conditions of 3-5 GPa, 800-1200 °C and the heat preservation for 15 min. Moreover, the sintering body of Cr3C2 compound with the relative density of 99.84% by simultaneously tuning the pressure-temperature conditions exhibited excellent mechanical properties: a Vickers hardness of 20.3 GPa and a fracture toughness of ~8.9 MPam1/2. These properties were much higher than that by using the previous methods. The temperature condition obtained good mechanical properties in the experiment was about 1/3 lower than that using any other methods owing to the high pressure.

The Characterization of Bovine Bone-Derived Hydroxyapatite Isolated Using Novel Non-Hazardous Method

2020 ◽  
Vol 45 ◽  
pp. 49-56
Author(s):  
Aniek Setiya Budiatin ◽  
Samirah ◽  
Maria Apriliani Gani ◽  
Wenny Putri Nilamsari ◽  
Chrismawan Ardianto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Extraction Method ◽  
Bovine Bone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Novel Method ◽  
Scanning Electron

Bovine bone is a considerable source for the production of hydroxyapatite. The recent study reported a novel method to extract hydroxyapatite from bovine bone without producing hazardous residue. The bovine bones were cut and boiled in the opened chamber followed by boiling in pressurized tank. The bones were then soaked into 95% ethanol. Calcination was then conducted in 800°C, 900°C and 1,000°C, for 2 hours. The result was then grinded and sieved. The powder then was characterized using Fourier transform infrared (FT-IR), Scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD) to measure the purity of hydroxyapatite. It is concluded that the hydroxyapatite derived from this process showed 100% purity, resulting 35.34 ± 0.39% w/w from the wet bone weight and 72.3% w/w from the dried weight. The present extraction method has been proven to yield high amount of pure hydroxyapatite as well as reducing the use of hazardous reagent.

Characterization of Shivirtui Zeolite Modified with Aluminum Oxyhydroxide Nanofibers

2019 ◽  
Vol 942 ◽  
pp. 40-49
Author(s):  
Yulia Murashkina ◽  
Olga B. Nazarenko
Keyword(s):  
Chemical Properties ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Aluminum Oxyhydroxide

Natural zeolite of Shivirtui deposit (Russia) was modified with nanofibers of aluminum oxyhydroxide AlOOH. Aluminum oxyhydroxide nanofibers were produced at the heating and oxidation of aluminum powder with water. The properties of modified zeolite were investigated by means of X-ray diffraction, transmission electronic microscopy, scanning electronic microscopy, low-temperature nitrogen adsorption, thermal analysis, and Fourier transform infrared spectroscopy. It was found that water content in the modified sample of zeolite was about 15 %. Based on the study of the physical and chemical properties, shivirtui zeolite modified with nanofibers of aluminum oxyhydroxide can be proposed for use as a flame-retardant additive to polymers.

Preparation and characterization of poly(3-glycidoxypropyltrimethoxysilane) nanocomposite using organophilic montmorillonite clay (Mag-cetyltrimethylammonium)

2019 ◽  
Vol 53 (28-30) ◽  
pp. 4313-4322 ◽  
Author(s):  
Nadia Embarek ◽  
Nabahat Sahli ◽  
Mohammed Belbachir
Keyword(s):  
Thermal Properties ◽  
Preparation Method ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
X Ray ◽  
The Matrix ◽  
Organophilic Clay ◽  
Linear Poly ◽  
Organophilic Montmorillonite

Nanocomposites of linear poly(3-glycidoxypropyltrimethoxysilane) based on Algerian natural organophilic clay: montmorillonite–cetyltrimethylammonium named Maghnite-CTA were prepared by enhancing the dispersion of the matrix polymer in sheets of the organoclay. The effect of the organoclay, used with different amounts (3, 5, and 7% by weight) and the preparation method were studied in order to determine and evaluate their structural, morphological and thermal properties. X-ray diffraction analysis of obtained nanocomposites showed a significant change in the distance interlayer of montmorillonite–cetyltrimethylammonium. Therefore, interlayer expansion and exfoliation of linear poly(3-glycidoxypropyltrimethoxysilane) between layers of montmorillonite–cetyltrimethylammonium were observed. The thermal properties of the prepared nanocomposites were given by thermogravimetric analysis. The structure and morphology of the obtained materials were determined respectively by Fourier transform infrared spectroscopy and scanning electronic microscopy. The results obtained have approved the privilege of the intercalation of linear poly(3-glycidoxypropyltrimethoxysilane) in the interface of montmorillonite–cetyltrimethylammonium and the best quantity of organoclay required to prepare nanocomposite with a high thermal stability is 5% (by weight).

Characterization of Spherical Molybdenum Powders Prepared by RF Plasma Processing

2012 ◽  
Vol 482-484 ◽  
pp. 2563-2567 ◽  
Author(s):  
Yan Wei Sheng ◽  
Zhi Meng Guo ◽  
Jun Jie Hao
Keyword(s):  
Feeding Rate ◽  
Morphological Properties ◽  
Narrow Particle Size Distribution ◽  
Rf Plasma ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Spheroidization ◽  
Powder Characteristics ◽  
Near Net Shape

Spherical molybdenum powders were synthesized by (RF) plasma with irregular molybdenum powders. The powder characteristics and spheroidization efficiency of the feeding rate for obtain the spherical molybdenum powders were studied. The phase composition and morphological properties of the powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). As a result, the fine spherical powders composed of pure molybdenum with favorable dispersity and its surface became smooth. The spheroidization efficiency of synthesized powders was almost 100 % at feeding rate of 5g/min. LMS analysis indicated that the as-prepared powder had narrow particle size distribution and the spheroidization efficiency of the sample decreases gradually as increasing of the feeding rate. The RF plasma spheroidization of molybdenum powder is an ideal route synthesis of well- spherical molybdenum powders used as near net-shape technology and powder metallurgy.

Development and Characterization of the Al2O3-YAG Ceramic Composites

2014 ◽  
Vol 798-799 ◽  
pp. 383-388 ◽  
Author(s):  
Eduardo Sousa Lima ◽  
A.P.O. Santos ◽  
L.M. Itaboray ◽  
C. Santos ◽  
R.F. Cabral
Keyword(s):  
Relative Density ◽  
Microstructural Characterization ◽  
Ceramic Composites ◽  
Oxide Ceramic ◽  
X Ray Diffraction ◽  
Powder Mixtures ◽  
X Ray ◽  
Resistance To Oxidation ◽  
Oxidation And Corrosion

YAG (Y3Al5O12) and Al2O3 ceramics have high resistance to oxidation and corrosion in harsh environments and high temperatures, which turns into a quite attractive material as compared to other ceramics. Thus, lately oxide ceramic YAG has been extensively used as reinforcement phase to Al2O3 in order to obtain a composite with improved mechanical properties. This research focused on the development of sintered Al2O3-Y2O3 powder mixtures for the production of Al2O3-YAG composite. Powder mixtures composed of 63.65:36.35wt.% and 80.00:20.00wt.% of Al2O3 and Y2O3, respectively, were milled by planetary milling for 2h. The compositions were compacted by cold uniaxial pressing, at 70 MPa, for 30s. The two mixtures were sintered at 1500 and 1600°C for 3h. The samples were evaluated for relative density, shrinkage, weight loss, and X-Ray Diffraction (XRD). Scanning Electron Microscopy (SEM) was used for microstructural characterization. The X-Ray Diffraction showed the presence of Al2O3 and Y3Al5O12 as crystalline phases in both compositions. Samples composed by 80:20wt.% of Al2O3/Y2O3 powder sintered at 16000C-3h presented the higher relative density ranging around 86% of theoretical density.

Preparation and Characterization of PbO2 Electrode Modified with Praseodymium

2013 ◽  
Vol 721 ◽  
pp. 37-40 ◽  
Author(s):  
Shu Dong Li ◽  
Feng Wu Wang ◽  
Mai Xu ◽  
Wen Yan Fang ◽  
Xiao Yun Yan
Keyword(s):  
Methylene Blue ◽  
Electrochemical Properties ◽  
Active Surface ◽  
Cyclic Voltammograms ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Bulk Electrolysis

The Ti/PbO2 electrode doped with Pr2O3 was prepared by the electrodeposition method. The X-ray diffraction (XRD) analyses indicated the crystal particles size of Ti/PbO2/Pr2O3 electrode was diminished due to the incorporation of Pr2O3 into the film of PbO2. The scanning electronic microscopy (SEM) revealed that Ti/PbO2/Pr2O3 electrode had smaller particles and larger active surface. The measurement of cyclic voltammograms (CV) revealed Ti/PbO2/Pr2O3 electrode had a better electrochemical properties comparing to Ti/PbO2 electrode. The bulk electrolysis demonstrated that the Ti/PbO2/Pr2O3 electrode presented excellent electrocatalytic performance for degradation methylene blue.

Contribution to a Technological Characterization of Kaolins from Cuba and Brazil

2006 ◽  
Vol 530-531 ◽  
pp. 720-727
Author(s):  
Guillermo Ruperto Martín Cortés ◽  
Wildor Theodoro Hennies ◽  
Francisco Rolando Valenzuela-Díaz
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Simple Description ◽  
X Ray ◽  
The Republic

This paper studies the main well-know technological types of kaolins clays from the Republic of Cuba and compares it with one from Brazil. A simple description from the Cuban geology and from the involved kaolins deposits is showed. The basic characterization of each kind of kaolin, includes, chemical analyzes, grain size distribution, scanning electronic microscopy, X-ray diffraction and X-ray fluorescence for chemicals. For special assays it had conformed, by a simple axis hand press up to 5 t, test bodies, which had been burnt to the temperatures of 950, 1250 and 1450°C. These results include refractory and contraction results.

scholarly journals Synchrotron x-ray microbeam diffraction from abalone shell

2004 ◽  
Vol 19 (5) ◽  
pp. 1471-1476 ◽  
Author(s):  
E. DiMasi ◽  
M. Sarikaya
Keyword(s):  
Self Assembly ◽  
Orientational Order ◽  
Amorphous Structure ◽  
Advanced Materials ◽  
Resolution Limit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Capillary Optics ◽  
Abalone Shell

Microstructured biomaterials such as mollusk shells receive much attention at present, due to the promise that advanced materials can be designed and synthesized with biomimetic techniques that take advantage of self-assembly and aqueous, ambient processing conditions. A satisfactory understanding of this process requires characterization of the microstructure not only in the mature biomaterial, but at the growth fronts where the control over crystal morphology and orientation is enacted. In this paper, we present synchrotron microbeam x-ray diffraction (XRD) and electron microscopy observations near the nacre–prismatic interface of red abalone shell. The relative orientations of calcite and aragonite grains exhibit some differences from the idealizations reported previously. Long calcite grains impinge the nacre–prismatic boundary at 45° angles, suggestive of nucleation on (104) planes followed by growth along the c axis. In the region within 100 μm of the boundary, calcite and aragonite crystals lose their bulk orientational order, but we found no evidence for qualitative changes in long-range order such as ideal powder texture or an amorphous structure factor. XRD rocking curves determined the mosaic of calcite crystals in the prismatic region to be no broader than the 0.3° resolution limit of the beamline’s capillary optics, comparable to what can be measured on geological calcite single crystals.

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