Combustion synthesis of mechanically activated powders in the Nb–Si system

2002 ◽  
Vol 17 (8) ◽  
pp. 1992-1999 ◽  
Author(s):  
Filippo Maglia ◽  
Chiara Milanese ◽  
Umberto Anselmi-Tamburini ◽  
Stefania Doppiu ◽  
Giorgio Cocco
Keyword(s):  
Mechanical Activation ◽  
Single Phase ◽  
Milling Time ◽  
Combustion Process ◽  
Temperature Wave ◽  
The Self ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Niobium Silicides ◽  
Reactant Powder

The effect of the mechanical activation of the reactants on the self-propagating high-temperature synthesis (SHS) of niobium silicides was investigated. SHS experiments were performed on reactant powder blends of composition Nb:Si = 1:2 and Nb:Si = 5:3 pretreated for selected milling times. A self-sustaining reaction could be initiated when a sufficiently long milling time was employed. At short milling times, the reactions self-extinguished or propagated in an unsteady mode. Combustion peak temperature, wave velocity, and product composition were markedly influenced by the length of the milling treatment. Single-phase products could be obtained for sufficiently long milling times. Observation of microstructural evolution in quenched reactions together with isothermal experiments allowed clarification of the mechanism of the combustion process and the role played by the mechanical activation of the reactants.

Alumina Whiskers Formation during Self-Propagation High-Temperature Synthesis

2007 ◽  
Vol 280-283 ◽  
pp. 1021-1022 ◽  
Author(s):  
Ling Zhen Zhang ◽  
Chun Chao Zhang
Keyword(s):  
Titanium Dioxide ◽  
High Temperature ◽  
Growth Mechanism ◽  
Raw Materials ◽  
Combustion Process ◽  
The Self ◽  
Combustion Mode ◽  
Temperature Synthesis ◽  
Aluminum Powders ◽  
High Temperature Synthesis

In this paper, the SHS process was accomplished using titanium dioxide and aluminum powders as raw materials. It was found that the combustion process exhibited the self-spiral combustion mode and alumina whisker had formed. The morphology, microstructure and growth mechanism of alumina whisker were investigated.

Influence of Cu addition on the self-propagating high-temperature synthesis of Ti5Si3 in Cu–Ti–Si system

2008 ◽  
Vol 111 (2-3) ◽  
pp. 463-468 ◽  
Author(s):  
H.Y. Wang ◽  
S.J. Lü ◽  
M. Zha ◽  
S.T. Li ◽  
C. Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
The Self ◽  
Temperature Synthesis ◽  
High Temperature Synthesis

Self-propagating high-temperature synthesis microalloying of MoSi2 with Nb and V

2003 ◽  
Vol 18 (8) ◽  
pp. 1842-1848 ◽  
Author(s):  
F. Maglia ◽  
C. Milanese ◽  
U. Anselmi-Tamburini ◽  
Z. A. Munir
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Tetragonal Phase ◽  
Synthesis Method ◽  
The Self ◽  
Alloying Elements ◽  
Alloying Element ◽  
Temperature Synthesis ◽  
Starting Mixture ◽  
High Temperature Synthesis

Microalloying of MoSi2 to form Mo(1−x)MexSi2 (Me = Nb or V) was investigated by the self-propagating high-temperature synthesis method. With alloying element contents up to 5 at.%, a homogeneous C11b solid solution was obtained. For higher contents of alloying elements, the product contained both the C11b and the hexagonal C40 phases. The relative amount of the C40 phase increases with an increase in the content of alloying metals in the starting mixture. The alloying element content in the hexagonal C40 Mo(1−x)MexSi2 phase was nearly constant at a level of about 12 at.% for all starting compositions. In contrast, the content of the alloying elements in the tetragonal phase is considerably lower (around 4 at.%) and increases slightly as the Me content in the starting mixture is increased.

scholarly journals Кластеризация марганца в ZnS : Mn, Mg, полученного методом высокотемпературного самораспространяющегося синтеза

2020 ◽  
Vol 54 (3) ◽  
pp. 259
Author(s):  
Ю.Ю. Бачериков ◽  
И.П. Ворона ◽  
О.Б. Охрименко ◽  
В.П. Кладько ◽  
А.Г. Жук ◽  
...  
Keyword(s):  
High Temperature ◽  
Luminescence Band ◽  
Lattice Strain ◽  
Nonuniform Distribution ◽  
The Self ◽  
Manganese Ions ◽  
Photoluminescence Band ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Mn Concentration

Abstract The ZnS:Mn, Mg powder is fabricated by self-propagating high-temperature synthesis with the simultaneous introduction of Mn and Mg impurities. It is found that the simultaneous introduction of Mn and Mg impurities leads to the nonuniform distribution of manganese forming regions with a lower and higher Mn concentration. In the latter case, the manganese ions form paramagnetic clusters. At the same time, numerous centers of self-activated luminescence form in the synthesized ZnS:Mn, Mg due to mechanical stress and lattice strain. Additional annealing leads to a more uniform Mn distribution in the formed ZnS:Mn, Mg phosphor, which is accompanied by an increase in the intensity of the manganese photoluminescence band and quenching of the self-activated luminescence band.

Microstructural aspects of the self-propagating high temperature synthesis of hexagonal barium ferrites in an external magnetic field

2000 ◽  
Vol 10 (8) ◽  
pp. 1925-1932 ◽  
Author(s):  
Louise Affleck ◽  
Marco D. Aguas ◽  
Ivan P. Parkin ◽  
Quentin A. Pankhurst ◽  
Maxim V. Kuznetsov
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
External Magnetic Field ◽  
The Self ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Barium Ferrites
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