Total and Partial Replacement of Quartz in Aluminum Hydroxides Porcelain Formulations

2014 ◽  
Vol 798-799 ◽  
pp. 289-293
Author(s):  
Guilherme Gralik ◽  
Adriana Scoton Antonio Chinelatto ◽  
Adilson Luiz Chinelatto
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Flexural Strength ◽  
Water Absorption ◽  
Aluminum Hydroxide ◽  
Raw Materials ◽  
Partial Replacement ◽  
X Ray ◽  
Aluminum Hydroxides ◽  
Scanning Electron

Alumina has been studied as a substitute for quartz triaxial porcelain formulations, but the high cost of the alumina raises the cost of production. The use of aluminum hydroxide from the Bayer process for obtaining aluminum, a source of alumina, is an alternative to alumina. In this work we used two aluminum hydroxides to replace the quartz composition of triaxial porcelain. The raw materials used were characterized by analysis of particle size distribution, scanning electron microscopy, diffraction and X-ray fluorescence. The compositions sintered were characterized by apparent density, apparent porosity, water absorption, flexural strength, and X-ray diffraction and scanning electron microscopy. Both the total and partial replacement of quartz by aluminum hydroxide showed good results with high flexural strength, low water absorption and low porosity.

Influence of Fly Ash on Corrosion Resistance of Refractory Forsterite-Spinel Ceramics

2021 ◽  
Vol 325 ◽  
pp. 181-187
Author(s):  
Martin Nguyen ◽  
Radomír Sokolář
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Fly Ash ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transition Zones ◽  
Refractory Ceramics ◽  
Scanning Electron

This article examines the influence of fly ash on corrosion resistance of refractory forsterite-spinel ceramics by molten iron as a corrosive medium. Fly ash in comparison with alumina were used as raw materials and sources of aluminium oxide for synthesis of forsterite-spinel refractory ceramics. Raw materials were milled, mixed in different ratios into two sets of mixtures and sintered at 1550°C for 2 hours. Samples were characterized by X-ray diffraction analysis and thermal dilatometric analysis. Crucibles were then made from the fired ceramic mixtures and fired together with iron at its melting point of 1535°C for 5 hours. The corrosion resistance was evaluated by scanning electron microscopy on the transition zones between iron and ceramics. Mixtures with increased amount of spinel had higher corrosion resistance and mixtures with fly ash were comparable to mixtures with alumina in terms of corrosion resistance and refractory properties.

Preparation and Properties of CaF2 Nano-Powder

2016 ◽  
Vol 680 ◽  
pp. 257-260
Author(s):  
Meng Yun Dong ◽  
Cheng Zhang ◽  
Jin Feng Xia ◽  
Hong Qiang Nian ◽  
Dan Yu Jiang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Sintering Temperature ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Powder ◽  
Direct Precipitation ◽  
Scanning Electron

CaF2 nano-power was prepared by direct precipitation methods with Ca(NO3)2 and KF as raw materials. The influences of presintering temperature and sintering temperature on the particle size and distribution of CaF2 nano-power were studied by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM). This study provided an experimental method for preparation of CaF2 nano-power. The results show that the best presintering temperature of CaF2 nano-power is 500°C and the best sintering temperature of CaF2 ceramic is 900°C.

Preparation and Properties of Sintering Brick from Iron Tailings

2012 ◽  
Vol 512-515 ◽  
pp. 1023-1027
Author(s):  
Ran Fang Zuo ◽  
Gao Xiang Du ◽  
Le Fu Mei ◽  
Wei Juan Guo ◽  
Jing Hui Liao
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Bulk Density ◽  
Raw Materials ◽  
Loss On Ignition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Freeze Thaw ◽  
Scanning Electron

The main objective of this paper was to investigate the addition of iron tailing sintering brick production, in the presence of clay, coal refuses and bentonite. Mixtures containing raw materials of sintering brick and iron tailings were prepared at different proportions (up to 55 wt %), fired at 980°C. Freeze/thaw durability, drying and firing shrinkages were investigated as well as the loss on ignition, bulk density and compressive strength of the fired samples. Their mechanical and microstructure properties were also investigated by differential thermal analysis (DTA/TG), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that compressive strengths of the brick samples are higher than that required by the standards MU15 of GB5101-2003, up to 21.79Mpa with 40% iron tailings corresponding to its higher bulk density completely. Moreover, the results showed that it has such advantages as no lime blowing, uniform color, good freeze/thaw resistance and slight universal frost.

Effects of Reductive Conditions on the Electrochemical Properties of LiFePO4/C Derived by Fe3+ Sources

2014 ◽  
Vol 1081 ◽  
pp. 313-317
Author(s):  
Yan Wen Lu ◽  
Yu Ge ◽  
Yue Feng Tang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Raw Materials ◽  
Thermal Method ◽  
X Ray Diffraction ◽  
Sintering Atmosphere ◽  
X Ray ◽  
Electrochemical Capacity ◽  
One Step ◽  
Scanning Electron

A one-step carbon thermal method was used to prepare LiFePO4/C particles by using normal Fe2O3, LiH2PO4and sucrose as raw materials. The effect of H2content in the sintering atmosphere of N2on the morphology and the electrochemical performance were investigated. LiFePO4/C materials were characterized by X-ray diffraction, scanning electron microscopy and the elemental analyzer. The results show that the precursor sintering under the atmosphere of 8%H2+N2exhibits the highest electrochemical capacity (162.3 mAh/g at 0.1C) .

STUDY OF MECHANICAL PROPERTIES AND FRACTURE MODE OF ALUMINA-SILICON CARBIDE NANOCOMPOSITES

2012 ◽  
Vol 05 ◽  
pp. 551-558 ◽  
Author(s):  
A. RAHIMNEZHAD YAZDI ◽  
H.R. BAHARVANDI ◽  
H. ABDIZADEH ◽  
N. EHSANI
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Silicon Carbide ◽  
Flexural Strength ◽  
Fracture Mode ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sic Particles ◽  
Scanning Electron

In this study Al 2 O 3- SiC nanocomposites have been fabricated by mixing of alumina and silicon carbide nano powders, followed by hot pressing at 1700°C. The mechanical properties and fracture mode of Al 2 O 3- SiC nanocomposites containing different volume fractions (5, 10 and 15%) of nano scale SiC particles were investigated and compared with those of alumina. Al 2 O 3- SiC powders were prepared by planetary milling in isopropanol. Fracture mode of specimens was investigated by means of scanning electron microscopy. Nanocomposites were tougher than alumina when they were hot pressed at the same temperature, and the values of nanocomposite's flexural strength and hardness were higher than those of alumina. Flexural strength, hardness and fracture toughness of the nanocomposites increase by increasing the volume percent of SiC up to 10% and then decrease slightly. The Scanning electron microscopy observations showed that fracture mode changes from intergranular for alumina to transgranular for nanocomposites. Finally X-ray diffraction analysis couldn't detect any chemical reactions between Al 2 O 3 and SiC particles.

Archaeometric analysis of a fragment of molded stucco cornice with rope from the House of the Mithraeum (Mérida, Spain)

2021 ◽  
pp. 1-22
Author(s):  
Alicia Fernández Díaz ◽  
Ana María Bejarano Osorio ◽  
Macarena Bustamante-Álvarez ◽  
Dolores Julia Yusá Marco ◽  
Sofía Vicente Palomino ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Diffraction Data ◽  
Raw Materials ◽  
Compositional Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Technical Study ◽  
Scanning Electron

Abstract During the excavations carried out since 2017 in the House of the Mithraeum (Casa del Mitreo) in Mérida a collection of paintings was recovered from Room 11, which had been abandoned in the late 3rd c. CE after a fire. The remains included fragments of molded stucco cornices, with braided esparto grass ropes on the reverse that were used to attach them to the ceiling. This article presents the descriptive and technical study of the finds and their compositional analysis using scanning electron microscopy and X-ray diffraction. Data resulting from these analyses allow us to understand the fragments’ composition and technical execution, and even the possible circulation of workshops and raw materials.

Preparation of Cordierite–Mullite Composite Crucibles and Structure Characterization

2012 ◽  
Vol 430-432 ◽  
pp. 521-524
Author(s):  
Feng Feng Li ◽  
Jiao Du ◽  
Ming Xi Zhang ◽  
Wei Chao Yang ◽  
Yi Shen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Raw Materials ◽  
Sintered Sample ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
State Process ◽  
Sintered Temperature ◽  
Scanning Electron

Cordierite–mullite composite crucibles were prepared via high-temperature solid-state process by using burn talc, datong soil, knar clay, bentonite, quartz, feldspar and alumina as raw materials, waste porcelain powder as skeletal material. The main influencing factors such as the raw materials radio and calcination temperature were discussed. The microstructure of the sintered sample was analyzed with X-ray diffraction (XRD) and Scanning electron microscopy (SEM). The results show that the optimal prescription was sample II (13.34 wt% of burn talc, 10.496wt% datong soil, 40.65% knar clay, 15.00wt% waste porcelain powder,10.34wt% bentonite, 2.17wt% feldspar, 1.61wt% quartz, and 6.394wt% of alumina). The optimal sintered temperature was 1380°C and the holding time was 3 hours.

Flexural Strength of Superfine Grained Si2N2O-Si3N4 Composites

2007 ◽  
Vol 353-358 ◽  
pp. 1477-1480
Author(s):  
Jun Ting Luo ◽  
Qing Zhang ◽  
Kai Feng Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Flexural Strength ◽  
Liquid Phase Sintering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value ◽  
Average Grain Size ◽  
Main Fracture ◽  
Scanning Electron

The Si3N4- Si2N2O composites were fabricated with amorphous nano-sized silicon nitride powders by the liquid phase sintering(LPS) method. The sintering temperatures ranged from 1500°C to 1700°C. Microstructure and component of the composites were performed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Results show that sintered body consists of Si2N2O and β-Si3N4, with an average grain size about 1μm. The maximum value of flexural strength of the material is 680MPa when sintered at 1700°C. Transcrystalline cracking is the main fracture mechanism of the composites.

Influence of Titanium Sol on the Sintering Behaviour, Microstructure and Properties of Al2O3-SiO2 Ceramic Cores

2013 ◽  
Vol 745-746 ◽  
pp. 507-511
Author(s):  
Jun Chen ◽  
Yue Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Flexural Strength ◽  
Room Temperature ◽  
Formation Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mullite Phase ◽  
Sintering Behaviour ◽  
Scanning Electron

A series of Al2O3-SiO2 ceramic cores with titanium sol sintered at 1350, 1450, 1500 and 1550for 2h, respectively, were prepared, and the phase and microstructure were characterized by X-ray Diffraction and Scanning Electron Microscopy. The influence of titanium sol on the phase transformation, shrinkage rate and flexural strength at room temperature has been investigated. The mullite phase formation temperature decreased by at least 150with the addition of 1wt% to 5wt% TiO2. Additionally, the titania additive promoted the combination of Al2O3 and SiO2, producing mullite phase which reduced the shrinkage and improved the flexural strength.

scholarly journals Rapid Synthesis of Dittmarite by Microwave-Assisted Hydrothermal Method

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Lai zhenyu ◽  
Qian Jueshi ◽  
Lu Zhongyuan ◽  
Li Qian ◽  
Zou Qiulin
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Hydrothermal Method ◽  
Raw Materials ◽  
Rapid Synthesis ◽  
X Ray ◽  
Microwave Assisted ◽  
Higher Temperature ◽  
Scanning Electron

Dittmarite was obtained using MgO and (NH4)2HPO4as raw materials via microwave-assisted hydrothermal method for 3 min at 120°C. The resulting samples were investigated by X-ray powder diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetry-differential thermal analysis. The results indicate that dittmarite can be rapidly synthesized by microwave-assisted hydrothermal method. With higher temperature and longer reaction time, highly crystallized dittmarite can be obtained. Pure dittmarite can be synthesized for 3 min at 120°C, which is faster than with the use of any other reported methods.

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