Synthesis of Ti3SiC2 in air using mechanically activated 3Ti/Si/2C powder

The Influence of Gas Atmosphere Composition on Formation of Surface Films in Self-propagating High-temperature Synthesis of Porous Ti3SiC2

“…From the results of elemental analysis of the chemical composition, it follows that a surface film must contain oxides and nitrides (Table 1). In previous work (Liang, et al, 2009) were found the formation of a film on the surface of the porous Ti 3 SiC 2 obtained from mechanically activated mixture of powders 3Ti+Si+2C through the performance of SHS process in the air. Based on the results of X-ray phase analysis, it was concluded that this oxide film consists mainly of titanium oxide (TiO 2 ).…”

“…In addition, SiO 2 is amorphous, therefore, when X-ray phase analysis is not detected. On the basis of the above, it was concluded that the surface film is an oxide film and is composed mainly of TiO 2 (Liang, et al, 2009). This film prevents the diffusion of oxygen deep into the porous preform, where the SHS reactions of the formation of titanium silicon carbide and titanium carbide are initiated under the action of heat generation of the surface oxidation:…”

“…Based on the results of X-ray phase analysis, it was concluded that this oxide film consists mainly of titanium oxide (TiO 2 ). A scheme of self-ignition of the mechanically activated initial mixture of powders in the air and initiation of the SHS process was also proposed (Liang, et al, 2009). The self-ignition starts due to reactions between components of the activated mixture on the surface of the preform with oxygen:…”

“…The first group includes methods of reaction sintering of a mixture of powders of starting components with external high-temperature heating and with the application of pressure or without the application of pressure (Fraczkiewicz, et al, 2006;Li, et al, 2004;Sun, et al, 2005;Zhou, et al, 2014). The second group consists of methods of self-propagating high-temperature synthesis (SHS) by burning a mixture of powders, when high temperatures are reached not due to external electrical heating, but due to the internal heat of combustion (Pampuch, et al, 1989;Liang, et al, 2009;Meng, et al, 2013). In the first group, an expensive energy-intensive equipment is used, whereas in the second group it is a simple equipment with low energy consumption, so SHS methods are seen as more economical for the organization of industrial production of Ti 3 SiC 2 materials and from this point of view, they are relevant for further improvement (Liang, et al, 2009;Meng, et al, 2013).…”

“…Another area of improvement could be the formation of functional coatings on the surface of the porous Ti 3 SiC 2 , and here we can mention only one study (Liang, et al, 2009), in which the formation of an oxide layer of TiO 2 on the surface of the porous Ti 3 SiC 2 was observed when it was obtained from mechanically activated mixture of powders 3Ti+Si+2C through the performance of SHS process in the air. It is known that the functional coating can significantly improve the performance characteristics of porous materials: physical, mechanical, corrosive, catalytic, biocompatible (Vityaz, et al, 2010;Ilyushenko, et al, 2010;Smorygo, et al, 2008;Browne & Gregson, 1994;Sul & Johansson, 2005).…”