Combustion Synthesis of Nanosized β-SiC Powder on a Large Scale

Abstract

Nanosized β-SiC powder was prepared by combustion synthesis on a large scale, which was carried out in a N 2 atmosphere with silicon powder and carbon black as the reactants. Mechanical activation played an important role in enhancing the reactivity of the reactants, and a higher ball/charge weight ratio and a prolonged activation time were favorable for complete reaction. PTFE was added as a reaction promoter, which remarkably reduced the minimum activation time required for successful combustion synthesis. On the basis of experimental results and thermodynamical calculation, it is proposed that combustion synthesis of SiC in N 2 includes two steps: (1) Si reacts with N 2 to form Si 3 N 4 , generating a lot of heat energy; (2) at higher temperatures the initially formed Si 3 N 4 decomposes, and released Si reacts with carbon to produce SiC.

Large-scale synthesis of few-layer graphene from magnesium and different carbon sources and its application in dye-sensitized solar cells

“…Self-propagating high-temperature synthesis (SHS) is a method of combustion synthesis, which denotes highly exothermic processes leading to solid-state products [23]. Since its discovery in the early 1970s [24,25], SHS has attracted more and more attentions as an alternative method to the conventional furnace technology for the synthesis of a variety of advanced materials such as carbides, nitrides, borides and oxides [26][27][28][29][30][31][32]. SHS is characterized by the fact that the reaction is initiated at one end of the sample, and selfpropagates through the reactants in the form of a combustion wave at a velocity which varies from 0.1 to 25 cm s -1 .…”

Combustion of heterogeneous nanostructural systems (Review)

“…One of the research directions is chemical activation. Addition of several percent of NH 4 Cl to the mechanically activated mixture Si + C allowed initiation of combustion at room temperature (this composition usually requires significant heating) and obtaining fine-grain silicon carbide [62,63]. By adding KNO 3 (20 wt.%) to the Fe-Si system, stable combustion was provided and iron silicides with a fine-grain microstructure were obtained [64].…”

Combustion Synthesis of Ceramic Powders with Controlled Grain Morphologies

“…Because (Si+C) system is weakly exothermic, combustion synthesis of SiC requires extra energy input by mechanical activation, preheating, microwave radiation, or electric field activation. Combustion synthesis of SiC can also be carried out in a highpressure N 2 atmosphere, where nano-sized powders can be obtained [13]. Figure 11 shows the photographs of SiC product prepared by combustion synthesis in N 2 .…”