Experimental investigation of mechanical, thermal, and ablation performance of ZrO ₂ /SiC modified C‐Ph composites

Abstract In this study, an effort has been made to improve the mechanical, thermal, and ablation performance of carbon‐phenolic (C‐Ph) composites. The ZrO ₂ , SiC, and ZrO ₂ /SiC hybrid fillers were synthesized using sol‐gel method followed by individual incorporation into C‐Ph composites. The thermal stability and flexural strength of these C‐Ph composites were analyzed using thermogravimetry analysis and three‐point bending test, respectively. A significant improvement in the flexural strength and modulus of the reinforced C‐Ph composites was observed and also exhibited the higher thermal stability. The oxyacetylene flame test was conducted to measure the ablation behavior of these filler reinforced C‐Ph composites under a heat flux of 4.0 MW /m ² for 60 seconds. ZrO ₂ /SiC0.5 reinforcement in the C‐Ph composite decreased the linear and mass ablation rates by 46% and 22%, respectively when compared with pure C‐Ph composite. The surface morphology analysis revealed that the burnt composite covered with the ZrC ceramic phase and SiO ₂ bubble‐like structure, which could have improved the ablation resistance of composites. These results were found well within the acceptable range when using the surface energy dispersive spectroscopy and X‐ray diffraction analysis.