scholarly journals The influence of compaction pressure on the density and electrical properties of cordierite-based ceramics

2015 ◽  
Vol 47 (1) ◽  
pp. 15-22 ◽  
Author(s):  
N. Obradovic ◽  
N. Djordjevic ◽  
A. Peles ◽  
S. Filipovic ◽  
M. Mitric ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Ball Mill ◽  
Compaction Pressure ◽  
High Energy ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Air Atmosphere ◽  
High Energy Ball Mill ◽  
Energy Ball

Due to its characteristics, cordierite, 2MgO?2Al2O3?5SiO2, is a high-temperature ceramic material of a great scientific interest. Mechanical activation of the starting mixtures containing 5.00 mass% TiO2 was performed in a high-energy ball mill for 10 minutes. The compaction pressure varied from 0.5 to 6tcm-2 (49-588 MPa). The sintering process was performed at 1350?C for four hours in the air atmosphere. The phase composition of the activated and sintered samples was analyzed using X-ray diffraction. Scanning electron microscopy was used to analyze the microstructure of both compacted and sintered samples. The authors have investigated the influence of compaction pressure on the sintered samples and their electrical properties.

scholarly journals Influence of prolonged sintering time on density and electrical properties of isothermally sintered cordierite-based ceramics

2013 ◽  
Vol 45 (2) ◽  
pp. 157-164 ◽  
Author(s):  
A. Peles ◽  
N. Djordjevic ◽  
N. Obradovic ◽  
N. Tadic ◽  
V.B. Pavlovic
Keyword(s):  
Electrical Properties ◽  
Mechanical Activation ◽  
Compaction Pressure ◽  
High Energy ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Air Atmosphere ◽  
Atomic Force ◽  
Sintering Time ◽  
High Energy Ball Mill

Mechanical activation is a commonly used and relatively fast and inexpensive procedure for sample preparation before the sintering process. Cordierite, a stoichiometric mixture of three different oxides (2MgO?2Al2O3?5SiO2) is a very attractive, widely used high-temperature ceramic material. The mechanical activation of the starting mixtures with 5.00 mass% TiO2 was performed in a high energy ball mill during 10-80 min. The applied compaction pressure before the sintering process was 2t/cm2, based on our recent investigation. The sintering process was performed at 1350oC for 2h and 4h in air atmosphere. X-ray diffraction was used to analyze the phase composition of non-activated and 80 min activated samples, sintered for 2 and 4h, respectively. Scanning electron microscopy was performed to analyze the microstructure of both compacted and sintered samples. Atomic force microscope was used to investigate the surface of the sintered samples. This paper investigates the influence of prolonged sintering time on the densities of the sintered samples, along with electrical properties.

Sintering of Al4C3 Using Aluminum Scrap and Commercial Graphite

2014 ◽  
Vol 802 ◽  
pp. 66-71
Author(s):  
Rodrigo Estevam Coelho ◽  
D.B. Silvany ◽  
M.D.C. Sobral ◽  
M.C.A. Silva
Keyword(s):  
Ball Mill ◽  
Graphite Powder ◽  
High Energy ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Aluminum Scrap ◽  
X Ray ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
Scanning Electron

In this works, aluminum scraps powders were mixed with commercial graphite and mechanically alloyed in a high-energy ball mill and subsequently powders sintering. The initial grinding of aluminum scraps for 2 hours and then mixed with commercial graphite powder at a proportion of (y)Al-(x)C (wt%) (x = 1, 5 e 10, 25). The mixture of aluminum and graphite powders was processed for a time at 5 hours of milling. The samples were sintered at a temperature of 750°C and 1000°C. Samples were analyzed by scanning electron microscopy and X-ray diffraction. The results of this study were to find important parameters of composition and sintering, because the increase in concentration of carbon in the aluminum indicates that the material may have different applications.

Effect of the Calcination Time of Fish Bones in the Synthesis of Hydroxyapatite

2005 ◽  
Vol 498-499 ◽  
pp. 600-605 ◽  
Author(s):  
W.M. Lima ◽  
W.R. Weinand ◽  
O.A.A. dos Santos ◽  
A. Paesano ◽  
F.H.M. Ortega
Keyword(s):  
Ball Mill ◽  
High Energy ◽  
X Ray Diffraction ◽  
Calcination Time ◽  
X Ray ◽  
Fish Bones ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
Combination Of Methods ◽  
Scanning Electron

In this work, a combination of methods for HAp synthesis is investigated. Fish bones were calcined at 900oC between 4h and 12h, followed by milling in a high-energy ball mill, by 2h and 4h at 300rpm. The obtained material was characterized by using techniques such as laser granulometry, X-ray diffraction, scanning electron microscopy (SEM) and atomic absorption spectroscopy. The performed analysis permitted us to obtain the Ca/P ratio, the morphology and the phase structure of hydroxyapatite particles powder.

Microstructural Evolution of Cr-Ta Powder in the Process of Mechanical Alloying

2015 ◽  
Vol 1094 ◽  
pp. 300-304
Author(s):  
Jing Yao ◽  
Shi Qiang Lu ◽  
Xuan Xiao
Keyword(s):  
Mechanical Alloying ◽  
Ball Mill ◽  
Supersaturated Solid Solution ◽  
High Energy ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Energy Ball Mill ◽  
The Hours ◽  
Energy Ball

High energy ball mill tests under the condition of the ball material mass ratio 13:1 and the rotate speed 400 r/min have been employed to investigate the process of mechanical alloying (MA) of Ta and Cr powder mixed in the mole ratio of 1:2.The microstructure evolution process and phase composition were explained useing scanning electron microscope (SEM) and X-ray diffraction (XRD). The results show that, the milled 20h powder existed in Ta (Cr) supersaturated solid solution and amorphous after 40h. Although the hours were spent on ball milling reached to 50h, Laves phase TaCr2had not been made during the process.

Nanostructure Evolution Evolution of Expanded Graphite during High-Energy Ball-Milling and Subsequently Annealing

2014 ◽  
Vol 552 ◽  
pp. 331-334
Author(s):  
Zhi Guo Liu
Keyword(s):  
Ball Milling ◽  
Expanded Graphite ◽  
High Energy ◽  
High Energy Ball Milling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Air Atmosphere ◽  
Vacuum Atmosphere ◽  
Energy Ball ◽  
Crystallization Degree

Expanded graphite (EG) was ball-milled in a high-energy mill (planetary-type) under an air atmosphere and subsequently annealed under a vacuum atmosphere. The products were characterized by X-ray diffraction (XRD). The results show that the ball-milling decreases the crystallization degree of EG, however, the subsequent annealing improves the crystallization degree of the ball-milled EG.

Preparation of Nano-fcc Structure Co Powders by High Speed Ball Milling

2013 ◽  
Vol 803 ◽  
pp. 308-311
Author(s):  
Ying Deng ◽  
Xiang Xiong ◽  
Yan Hua Zhang ◽  
Ling Ling Peng
Keyword(s):  
Ball Milling ◽  
High Speed ◽  
Spherical Shape ◽  
High Energy ◽  
Decomposition Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
Fcc Structure

High-energy ball mill of a mixture of H2C2O4·2H2O, Co (NO3)2·6H2O(A.R) has been used to produce nanocrystalline cobalt oxalate powders of nearly spherical shape. After the CoH2C2O4·2H2O powders have been dispersed by spray-drying, it has been decomposed at 400~550°C to obtain cobalt powders. The microstructure of the powders produced using ball milling and thermodynamical analysis for reaction and decomposition temperature have been studied. The powders were characterized by X-ray Diffraction, Scanning Electron Microscopy. It has been identified that a spherical, fcc structure, 100nm β-Co powders was synthesized.

The use of polymeric milling media in the reduction of contamination during mechanical attrition

2002 ◽  
Vol 17 (12) ◽  
pp. 2997-2999 ◽  
Author(s):  
Claudio L. De Castro ◽  
Brian S. Mitchell
Keyword(s):  
Stainless Steel ◽  
Thermogravimetric Analysis ◽  
Crystallite Size ◽  
Ball Mill ◽  
High Energy ◽  
Organic Contamination ◽  
X Ray ◽  
Mechanical Attrition ◽  
High Energy Ball Mill ◽  
Energy Ball

Aluminum samples were milled in a high-energy ball mill at times ranging from 10 to 500 min in stainless vial/media and nylon vial/media. The crystallite size of aluminum milled in the stainless steel setup reached a plateau at 25 nm around 100 min, whereas the crystallite size of aluminum milled in the nylon setup reached the same plateau at 500 min. Contamination studies were conducted using x-ray fluorescence, hydrogen–carbon–nitrogen analysis, and thermogravimetric analysis. Although organic contamination due to the nylon milling media was high at 12 wt% when milled for 500 min, it is shown that the contaminant could be easily removed by thermal treatment.

A Study of Exchange-Coupling Effect on Nd2Fe14B / α-Fe Forming Core/Shell Shape

2007 ◽  
Vol 119 ◽  
pp. 147-150 ◽  
Author(s):  
Chang Woo Kim ◽  
Young Hwan Kim ◽  
Don Keun Lee ◽  
In Chul Jeong ◽  
Hae Woong Kwon ◽  
...  
Keyword(s):  
Exchange Coupling ◽  
Ball Mill ◽  
Coupling Effect ◽  
Chemical Reduction ◽  
High Energy ◽  
Shell Shape ◽  
Core Shell ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
Mill Process

We report the core/shell type as the interesting one of the various techniques to prepare exchange-coupled permanent magnet. In this study, the exchange-coupled Nd2Fe14B/α-Fe was prepared by high energy ball mill process and chemical reduction. Nd15Fe77B8 powder prepared by high energy ball mill process was coated with α-Fe nanoparticle by chemical reduction. α-Fe nanoparticle on the ball milled Nd15Fe77B8 was synthesized by chemical reduction with borohydride as a reducing agent in aqueous solution. After annealing, Nd2Fe14B/α-Fe forming core/shell shape has exchange-coupling effect and was identified by using XRD, FE-SEM, VSM, TMA and EDX.

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