scholarly journals Analysis of early-stage sintering mechanisms of mechanically activated BaTiO3

2006 ◽  
Vol 38 (3) ◽  
pp. 239-244 ◽  
Author(s):  
M.V. Nikolic ◽  
V.P. Pavlovic ◽  
V.B. Pavlovic ◽  
M.M. Ristic
Keyword(s):  
Barium Titanate ◽  
Temperature Interval ◽  
Ball Mill ◽  
Early Stage ◽  
Planetary Ball Mill ◽  
Heating Rates ◽  
Barium Titanate Powder ◽  
Powder Samples ◽  
Sintering Mechanisms

Barium-titanate powder was mechanically activated in a planetary-ball mill for 60 and 120 minutes. Non-isothermal sintering of non-activated and activated powder samples was investigated using a dilatometer in the temperature interval from room to 1380oC with three different heating rates (10, 20 and 30oC/min). Early-stage sintering mechanisms for all three types of samples were analyzed, showing significant differences between the non-activated and mechanically activated samples.

The Influence of Tribophysical Activation on Non-Isothermal Sintering of BaTiO3 Ceramics

2006 ◽  
Vol 514-516 ◽  
pp. 1566-1570 ◽  
Author(s):  
Vera P. Pavlović ◽  
Maria V. Nikolić ◽  
V. Spasojević ◽  
Jovan Blanuša ◽  
Ljiljana Živković ◽  
...  
Keyword(s):  
Barium Titanate ◽  
Powder Diffraction ◽  
Ball Mill ◽  
Room Temperature ◽  
Diffraction Method ◽  
Heating Rates ◽  
Technological Parameters ◽  
Dilatometric Analysis ◽  
X Ray ◽  
Scanning Electron

In this paper the influence of tribophysical activation on non-isothermal sintering of barium titanate has been investigated. BaTiO3 powders were tribophysically activated in a planetary ball mill for 0, 60 and 120 min., pressed and non-isothermally sintered up to 1380oC. Dilatometric analysis was performed in air in the temperature range from room temperature to 1380oC with heating rates of 10, 20 and 30oC/min. The samples were analyzed by the X-ray powder diffraction method. Investigation of the morphology of microstructure constituents was performed using the scanning electron microsocopy method. With the purpose of optimizing technological parameters the results obtained by microstructure analysis were correlated with the results of quantitative dilatometric analysis.

Fast, solvent-free and highly enantioselective fluorination of β-keto esters catalyzed by chiral copper complexes in a ball mill

2017 ◽  
Vol 19 (7) ◽  
pp. 1674-1677 ◽  
Author(s):  
Yifeng Wang ◽  
Haojiang Wang ◽  
Yidong Jiang ◽  
Cheng Zhang ◽  
Juanjuan Shao ◽  
...  
Keyword(s):  
Ball Mill ◽  
Copper Complexes ◽  
Solvent Free ◽  
Planetary Ball Mill ◽  
Keto Esters ◽  
Solvent Free Conditions

A fast and highly enantioselective fluorination of β-keto esters catalyzed by diphenylamine linked bis(oxazoline)-Cu(OTf)2 complexes under solvent-free conditions has been developed using a planetary ball mill.

scholarly journals Thermally stimulated oxygen desorption in Sr2FeMoO6-δ

2018 ◽  
Vol 4 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Nikolay A. Kalanda
Keyword(s):  
Activation Energy ◽  
Oxygen Diffusion ◽  
Gas Flow ◽  
Oxygen Vacancies ◽  
Early Stage ◽  
Diffusion Activation Energy ◽  
Energy Calculation ◽  
Heating Rates ◽  
Oxygen Desorption ◽  
Diffusion Activation

Polycrystalline Sr2FeMoO6-δ specimens have been obtained by solid state synthesis from partially reduced SrFeO2,52 and SrMoO4 precursors. It has been shown that during oxygen desorption from the Sr2FeMoO6-δ compound in polythermal mode in a 5%H2/Ar gas flow at different heating rates, the oxygen index 6-δ depends on the heating rate and does not achieve saturation at T = 1420 K. Oxygen diffusion activation energy calculation using the Merzhanov method has shown that at an early stage of oxygen desorption from the Sr2FeMoO6-δ compound the oxygen diffusion activation energy is the lowest Еа = 76.7 kJ/mole at δ = 0.005. With an increase in the concentration of oxygen vacancies, the oxygen diffusion activation energy grows to Еа = 156.3 kJ/mole at δ = 0.06. It has been found that the dδ/dt = f (Т) and dδ/dt = f (δ) functions have a typical break which allows one to divide oxygen desorption in two process stages. It is hypothesized that an increase in the concentration of oxygen vacancies Vo•• leads to their mutual interaction followed by ordering in the Fe/Mo-01 crystallographic planes with the formation of various types of associations.

scholarly journals Production of Ultrafine Particles by Continuous Planetary Ball Mill.

1991 ◽  
Vol 38 (2) ◽  
pp. 66-69
Author(s):  
Kantaro KANEKO ◽  
Mutsuhiro KAWASHIMA
Keyword(s):  
Ball Mill ◽  
Ultrafine Particles ◽  
Planetary Ball Mill

Antistatic Composite Coаtings on the Basis of Powder Paints

2014 ◽  
Vol 1040 ◽  
pp. 3-7
Author(s):  
Sergey Panin ◽  
Sergey Y. Yazykov ◽  
Boris Ovechkin
Keyword(s):  
Magnesium Alloy ◽  
Functional Properties ◽  
Powder Mixture ◽  
Ball Mill ◽  
Outer Space ◽  
Planetary Ball Mill ◽  
Static Electricity ◽  
Protective Function ◽  
Electrostatic Deposition ◽  
Space Conditions

For operating under outer space conditions besides providing originally specified protective function, coating should often ensure accomplishment of functional properties, for instance conductivity of electric current. The solution of this problem can be reached by adding powder fillers with specified functional properties into powder paint. The paper deals with development of technique for formation of protective conducting coatings by filling powder paints and treatment in planetary ball mill. For protection of magnesium alloy shells the technique is offered which combines formation of the oxidized sublayer, introduction of electroconductive filler, treatment of the powder mixture in the planetary ball mill and electrostatic deposition of sifted mixture of definite dispersion. This allows sinking of static electricity from cabinets of the equipment for the space-crafts applications in conditions of the outer space.

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