液相浸渍C/C复合材料反应生成TaC的形貌及其形成机制

采用Ta有机溶剂浸渍C/C复合材料,经固化、热处理制备C/C-TaC复合材料.研究发现:在2MPa浸渍压力下,Ta有机溶剂易于浸渍C/C复合材料和固化;1500℃热处理后,Ta有机溶剂全部转变为TaC,其尺寸细小,结晶度高,呈颗粒状或聚集成团簇均匀分布在热解炭层面上;1800和2000℃热处理后的TaC形貌与1500℃热处理后的相似,Tac颗粒无明显长大现象.Ta有机溶剂转化生成Tac的机理研究表明:热处理过程中,Ta有机溶剂先生成中间相的氧氟化钽,转变为Ta₂O₅后,再与C还原-化合生成TaC.

Morphology and Formation Mechanism of TaC Made by Liquid Phase Infiltration Method in C/C Composites

C/C composites were infiltrated with tantalum-contained organic solution, solidified and thermally treated to produce C/C-TaC composites. The results show that tantalum-contained organic solution easily infiltrates C/C composites and solidifies under 2MPa pressure. After treated at 1500℃, tantalum-contained organic solution tantalum completely turns into TaC with fine sizes and high crystallization, distributing on the layers of pyrolytic carbon with grains or clusters. The morphology of TaC made at 1800℃ and 2000℃ is analogous with that of made at 1500℃ and the grain size of TaC doesn’t grow up obviously. The mechanism research of tantalum-contained organic solution turning into TaC shows that it first turns into tantalum oxide fluoride, a kind of interphase, then Ta₂O₅ ultimately reduced and compounded by carbon into TaC.