Residual compressive and thermophysical properties of 4d carbon/carbon composites after repeated ablation under oxyacetylene flame of 3000 °C

The performance of carbon-carbon (C/C) composite's reusable parts regarding the extent of erosion, and residual mechanical and thermophysical properties in high temperature applications was studied. C/C composites were fabricated with fourdirectional preform architecture. The composites were repeatedly ablated using oxyacetylene flame of about 3000 °C for 30 s each time. The results show that the ablation rate of the composite is linearly proportional to the ablation time; a single step ablation shows a higher ablation rate as compared to the ablation carried out in steps, keeping the total ablation time the same. The surface roughness and exposure area of the specimen to the flame were found to significantly increase the ablation rate. The compressive strength, thermal conductivity and coefficient of thermal expansion (CTE) of the composite were found to decrease after every ablation test, whereas the specific heat capacity of the composite remained unchanged.