Abstract
Carbon fibers (CFs) are incorporated into ethylene propylene diene monomer (EPDM) rubber to fabricate charring elastomeric ablative composites for ultrahigh temperature applications. Ablation characteristics of the ablative composites were evaluated using ASTM E285-08. Variant content incorporation of short CFs in the basic composite formulation reduced the backface temperature acclivity and the ablation rate rose up to 48% and 78%, correspondingly. Thermal stability and endothermic capability were improved with increasing short fiber contents in the rubber matrix. Experimental thermal conductivity measurement results elucidate that thermal conductivity reduces 60% at 473 K with 6 wt% addition of the fibers. A remarkable improvement was scrutinized in the tensile strength and rubber hardness with increasing fiber to matrix ratio. Scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDS) analysis of the composite specimens revealed the uniform dispersion of CFs within the host matrix, formation of voids during ablation, char-reinforcement interaction and composition of the charred ablators and the impregnated fibers.