Formation Mechanism of TaC by Tantalum-contained Resin Precursor

C/C-TaC composites prepared by liquid precursors are promising in improving the ablation properties of C/C composites.The formation mechanism of TaC by tantalum-contained resin precursor was investigated through the analysis of components and morphologies of tantalum-contained resin after different heat treatment by XRD and SEM together with the DSC-TG results of tantalum-contained solution.The results show that tantalum-contained solution promotes the solidification of resin.Treated at 100℃,TaF_5 will hydrolyze into TaO_2F and the resin will solidify.Treated at 800℃in vacuum atmosphere,part of TaO_2F in tantalum-contained resin will decompose into Ta_2O_5 solid and TaF_5 gas. Then,Ta_2O_5 will be reduced and compounded by carbon into TaC with fine sizes at 1000℃.The loss of tantalum can be controlled by prolonging treatment time at lower temperatures (room temperature -100℃) and introducing anhydrous ammonia into the solution.