Pore Formation Process of Porous Ti(3)SiC(2) Fabricated by Reactive Sintering

Porous Ti(3)SiC(2) was fabricated with high purity, 99.4 vol %, through reactive sintering of titanium hydride (TiH(2)), silicon (Si) and graphite (C) elemental powders. The reaction procedures and the pore structure evolution during the sintering process were systematically studied by X-ray diffraction (XRD) and scanning electron microscope (SEM). Our results show that the formation of Ti(3)SiC(2) from TiH(2)/Si/C powders experienced the following steps: firstly, TiH(2) decomposed into Ti; secondly, TiC and Ti(5)Si(3) intermediate phases were generated; finally, Ti(3)SiC(2) was produced through the reaction of TiC, Ti(5)Si(3) and Si. The pores formed in the synthesis procedure of porous Ti(3)SiC(2) ceramics are derived from the following aspects: interstitial pores left during the pressing procedure; pores formed because of the TiH(2) decomposition; pores formed through the reactions between Ti and Si and Ti and C powders; and the pores produced accompanying the final phase synthesized during the high temperature sintering process.