Inhibitors treated C/C composites were manufactured by conventional liquid impregnation technique in order to study the effects of the inhibitors on the oxidation temperature of the C/C composites. Experiments were performed systemetically using $L_82^7$ orthogonal array table of the experimental design. In the experimental design, the $ZrB_2$, B, $SiB_4$, TEOS, TBP content and $H_3PO_4$ treatment were considered as thermal oxidation variables of C/C and the effects of the variables on the oxidation temperature of C/C composite were investigated.
The analysis of variance for experimental results indicated that $H_3PO_4$ washing was the most significant variable in the oxidation temperature of 20 wt% loss from the initial weight of inhibitor treated C/C composites. The oxidation test(TGA) has shown that the oxidation temperature of inhibited C/C was increased by 150℃ compared with the bare C/C composites. And then $ZrB_2$, B, TEOS, and TBP had less significance on the inhibition effect of C/C composites.
