Influence of Fe Addition on Products of Self-Propagating High-Temperature Synthesis Reaction in 3Ti-Si-2C System

来源期刊：稀有金属材料与工程2009年增刊第3期

论文作者：Si W P Wang H Y Li S L Jiang Q C Guan Q L

关键词：Ti_3SiC_2; self-propagating high-temperature synthesis (SHS); intermitallics; ceramics;

摘    要：Influence of Fe addition on products of self-propagating high-temperature synthesis (SHS) reaction in 3Ti-Si-2C system was investigated in the present study. Without Fe addition, Ti_5Si_3 and TiC are the dominant phases along with a small amount of Ti_3SiC_2 phase and unreacted C left in the final products. As Fe content ranges from 10% to 30%, the products consist of TiC, Ti_5Si_3, Fe_2Ti and unreacted C, but no trace of Ti_3SiC_2 phase is detected. Furthermore, the amounts of both Fe_2Ti and C phases increase with Fe content increasing. Addition of Fe has a great effect on the reaction route and significantly restrains the formation of Ti_3SiC_2 during the combustion synthesis process, and therefore, the SHS is not an effective fabrication technique to synthesize the ternary Ti_3SiC_2 ceramic in either 3Ti-Si-2C or Fe-3Ti-Si-2C system. Besides, without Fe addition, Ti_5Si_3 presents as the coarse irregular appearance with an obviously sintered morphology. In contrast, the shape of Ti_5Si_3 exhibits more and more spherical (cobblestone-like) and the surface becomes increasingly smooth, because the amount of liquids formed during the SHS reaction increases with the increase of Fe content. On the other hand, with Fe content increasing from 0 to 30 wt.%, the particulate size of TiC decreases from more than 5 μm to 1 μm or less, mainly due to the fact that the combustion temperature decreases with the increase of Fe content in the preforms.