Dynamically Controlled Formation of TiN by Combustion of Ti in Air

Abstract

This paper studies the formation of titanium nitride (TiN) by combustion of Ti particles in air. It is proposed that the combustion reaction is a dynamically controlled process, in which the formation of TiN is fulfilled by delayed gas infiltration behind the propagation of combustion wave. With the addition of NH4Cl or carbon black, the yield of TiN can be enhanced. The as‐synthesized TiN grains show a terraced morphology with parallel layers stacked in the normal direction. It is thought that this terraced morphology has been derived from a surface‐coarsening process. The parallel layers show regular hexagonal outlines and thus are considered to be (111) planes according to the symmetric characters of the FCC structure. The (111) texture is also revealed by X‐ray diffraction results, where the relative intensity of (111) peak is clearly higher than the reference in the JCPDS card. In addition, nanoscale twinning areas are observed in TiN grains. From transmission electron microscopy (TEM) results, it is determined that the twinning plane is (111) and the twinning direction is [211]. The movement of atoms during twinning is discussed according to the FCC structure of TiN and high‐resolution TEM images.

Effects of Si source and high gravity on combustion synthesis of Ti3SiC2in air

“…The formation of TiO 2 is reasonable because combustion synthesis was carried out in air. No oxide phases were found in the centre or lower part of the sample, which can be attributed to relatively slow diffusion of O 2 molecules in contrast to fast combustion reaction 17. 18 Besides TiC, TiSi 2 was another phase that was observed in every part of the product.…”

“…No oxide phases were found in the centre or lower part of the sample, which can be attributed to relatively slow diffusion of O 2 molecules in contrast to fast combustion reaction. 17,18 Besides TiC, TiSi 2 was another phase that was observed in every part of the product. Because SiC was the only one Si containing compound in the starting reactant, TiSi 2 is thought to be produced by the reaction between Ti and SiC.…”

Effect of reaction atmosphere on combustion synthesis of Ti2AlN

“…Similar results were observed for the combustion of pure Al, Ti and (AlzCzSi 3 N 4 ) powders. [12][13][14] In the combustion reaction, the nitridation of Ti is a major source of the generation of heat energy. Hence, the combustion temperature is determined to a large extent by the nitridation reaction.…”

Combustion Synthesis of Si3N4 by Selective Reaction of Silicon with Nitrogen in Air

“…For example, combustion of ultra‐fine Al particle and (Al+C) powders in air led to the formation of Al N instead of Al 2 O 3 7,8 . The TiN powder could also be synthesized by combustion of Ti powder in air 9 . These results suggest that single‐phase nitrogen ceramics could be synthesized through the selective nitriding combustion of metallic powders with N 2 in air, which provides a possibility of synthesis and sintering of nitrogen ceramics in a conventional kiln furnace without any atmosphere protection.…”