Synthesis and characterization of SiC ultrafine particles by means of sol-gel and carbothermal reduction methods

2015 ◽  
Vol 41 (4) ◽  
pp. 5779-5784 ◽  
Author(s):  
Zahra Omidi ◽  
Ali Ghasemi ◽  
Saeed Reza Bakhshi
2012 ◽  
Vol 557-559 ◽  
pp. 644-648 ◽  
Author(s):  
Qing Hua Yang ◽  
Huan Ping Wang ◽  
Wen Juan Zhang ◽  
Shi Feng Wang ◽  
Shi Qing Xu

Nano-sized aluminum nitride (AlN) powders were synthesized through a carbothermal reduction nitridation (CRN) route from a sol-gel low temperature combustion precursor. The precursor was precalcined at 600-1200 °C and then nitrided at 1400-1550 °C for different holding time to obtain AlN powders. During the whole preparation process, the amorphous alumina in the precursors first transformed to γ-Al2O3, then to α-Al2O3, and AlN was obtained through the nitridation of α-Al2O3with the reduction of carbon. The results show that the appropriate precalcination benefits the activity of precursors and promotes the formation of AlN phase due to the transition of amorphous alumina to γ-Al2O3, and the optimum precalcination temperature is 1000 °C. The effects of different nitridation parameters on the microstructure of AlN powders were also investigated. By being nitrided at 1500-1550 °C for 2 h, the AlN powders present a good distribution and small particle size of 30-90 nm from the precursor precalcinated at 1000 °C.


2002 ◽  
Vol 126 (2) ◽  
pp. 161-165 ◽  
Author(s):  
Junying Zhang ◽  
Zhongtai Zhang ◽  
Zilong Tang ◽  
Zishan Zheng ◽  
Yuanhua Lin

2014 ◽  
Vol 121 ◽  
pp. 20-29 ◽  
Author(s):  
Tim Van Gestel ◽  
Felix Hauler ◽  
Martin Bram ◽  
Wilhelm A. Meulenberg ◽  
Hans Peter Buchkremer

2003 ◽  
Vol 800 ◽  
Author(s):  
Brady J. Clapsaddle ◽  
Lihua Zhao ◽  
Alex E. Gash ◽  
Joe H. Satcher ◽  
Kenneth J. Shea ◽  
...  

ABSTRACTIn the field of composite energetic materials, properties such as ingredient distribution, particle size, and morphology, affect both sensitivity and performance. Since the reaction kinetics of composite energetic materials are typically controlled by the mass transport rates between reactants, one would anticipate new and potentially exceptional performance from energetic nanocomposites. We have developed a new method of making nanostructured energetic materials, specifically explosives, propellants, and pyrotechnics, using sol-gel chemistry. A novel sol-gel approach has proven successful in preparing metal oxide/silicon oxide nanocomposites in which the metal oxide is the major component. Two of the metal oxides are tungsten trioxide and iron(III) oxide, both of which are of interest in the field of energetic materials. Furthermore, due to the large availability of organically functionalized silanes, the silicon oxide phase can be used as a unique way of introducing organic additives into the bulk metal oxide materials. As a result, the desired organic functionality is well dispersed throughout the composite material on the nanoscale. By introducing a fuel metal into the metal oxide/silicon oxide matrix, energetic materials based on thermite reactions can be fabricated. The resulting nanoscale distribution of all the ingredients displays energetic properties not seen in its microscale counterparts due to the expected increase of mass transport rates between the reactants. The synthesis and characterization of these metal oxide/silicon oxide nanocomposites and their performance as energetic materials will be discussed.


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