The self-propagating high-temperature synthesis (SHS) of ultrafine high-purity TiC powder from TiO2+Mg+C

1995 ◽  
Vol 30 (11) ◽  
pp. 2835-2837 ◽  
Author(s):  
S. G. Ko ◽  
C. W. Won ◽  
B. S. Chun ◽  
H. Y. Sohn
1996 ◽  
Vol 11 (7) ◽  
pp. 1825-1830 ◽  
Author(s):  
J. C. Jung ◽  
S. G. Ko ◽  
C. W. Won ◽  
S. S. Cho ◽  
B. S. Chun

High-purity tungsten was prepared by the self-propagating high-temperature synthesis (SHS) process from a mixture of CaO · WO3 and Mg. The complete reduction of CaO · WO3 required a 33% excess of magnesium over the stoichiometric molar ratio Mg/CaO · WO3 of 3: 1. The MgO and CaO in the product were leached with an HCl solution. The product tungsten had a purity of 99.980% which was higher than that of the reactants. The high purity results because the nontungsten reactants and products are volatilized by the high temperatures generated during the rapid exothermic SHS reaction and are dissolved during HCl leaching of the product.


1995 ◽  
Vol 10 (4) ◽  
pp. 795-797 ◽  
Author(s):  
Seog Gueon Ko ◽  
Chang Whan Won ◽  
Byong Sun Chun ◽  
H.Y. Sohn

High-purity tungsten was prepared by the self-propagating high-temperature synthesis (SHS) process from a mixture of WO3 and Mg. The MgO in the product was leached with an HCl solution. The complete reduction of WO3 required a 33% excess of magnesium over the stoichiometric molar ratio Mg/WO3 of 3. The product tungsten had a purity of 99.980% which was higher than that of the reactant WO3. This is because the impurities were either volatilized at the high temperatures generated during the rapid exothermic reaction or dissolved into the HCl solution during leaching.


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

2003 ◽  
Vol 18 (8) ◽  
pp. 1842-1848 ◽  
Author(s):  
F. Maglia ◽  
C. Milanese ◽  
U. Anselmi-Tamburini ◽  
Z. A. Munir

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.


Author(s):  
Ю.Ю. Бачериков ◽  
И.П. Ворона ◽  
О.Б. Охрименко ◽  
В.П. Кладько ◽  
А.Г. Жук ◽  
...  

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.


2000 ◽  
Vol 10 (8) ◽  
pp. 1925-1932 ◽  
Author(s):  
Louise Affleck ◽  
Marco D. Aguas ◽  
Ivan P. Parkin ◽  
Quentin A. Pankhurst ◽  
Maxim V. Kuznetsov

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