Synthesis of dense Ti3SiC2-based ceramics by thermal explosion under pressure
Synthesis of dense Ti3SiC2-based ceramics by thermal explosion under pressure
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DOI：
10.1016/s0955-2219(02)00076-6
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发表时间：
2003
影响因子：
5.7
通讯作者：
Y. Khoptiar;I. Gotman
中科院分区：
文献类型：
--
作者：
Y. Khoptiar;I. Gotman
采用不同的SHS模式：波传播和无压或压力辅助热爆，研究了元素粉末自蔓延高温合成Ti3SiC2。SHS反应在低于任一组分的熔点的固态下被点燃，并开始形成Ti5Si3和富Ti的TiC1 − x。Ti3SiC2的形成发生在后期，从液体结晶的同时，化学计量的TiC沉淀。在这两种方法中，获得单相Ti3SiC2材料，燃烧产物含有可观量的TiC。另外一个"相"的组成近似为35Ti-52Si-14C（at. %），推测为Ti3SiC2-TiSi2-SiC低共熔混合物，在所有类型的样品中检测到。在热爆炸（反应性锻造）期间短时间施加80 MPa的中等压力1分钟，产生了含有1045体积%的95%的致密样品。Ti3SiC2。由于样品不含开孔孔隙率，因此可以在1500 ° C左右的温度下进一步进行HIPing而无需封装，以产生完全致密的单相Ti3SiC2。
Self-propagating high-temperature synthesis (SHS) of Ti3SiC2from the elemental powders employing different SHS modes: wave propagation and pressureless or pressure-assisted thermal explosion, has been studied. SHS reaction was ignited in the solid state below the melting point of either constituent, and started with the formation of Ti5Si3and Ti-rich TiC1−x. The formation of Ti3SiC2took place at the later stage by crystallization from the liquid concurrent with precipitation of the stoichiometric TiC. In neither approach, a single-phase Ti3SiC2material was obtained, the combustion products containing appreciable amounts of TiC. An additional ‘phase’ with the approximate composition of 35Ti–52Si–14C (at.%), supposedly the Ti3SiC2–TiSi2–SiC eutectic mixture, was detected in all types of samples. A short 1 min application of a moderate 80 MPa pressure during thermal explosion (reactive forging) yielded ⩾95% dense samples containing ∼45 vol.% Ti3SiC2. As the samples do not contain open porosity, they can be further used for HIPing without encapsulation at around 1500 °C to produce fully dense single-phase Ti3SiC2.