Effects of Si source and high gravity on combustion synthesis of Ti 3 SiC 2 in air

Abstract

Combustion synthesis of Ti₃SiC₂ was carried out in air with Si₃N₄, SiC, and Si as Si sources respectively, and the effect of Si source on the phase composition of the products was investigated. With Si₃N₄ as Si source, the major product was TiC_xN_1−x and no Ti₃SiC₂ was synthesised. When SiC and Si were used, Ti₃SiC₂ was synthesised. Such effect of Si source is thought to be connected with the formation mechanism of Ti₃SiC₂, where the presence of a Ti–Si melt is required. The combustion synthesis was also performed under high gravity condition instead of common gravity. The apparent density of the product prepared under high gravity was ∼60% higher than that obtained under normal gravity. It is proposed that, the high gravity can facilitate the permeation of Ti–Si melt and enlarge the interface between the melt and carbide phases, which is helpful for the formation of Ti₃SiC₂.