Effect of ZrB₂ Dominate with SiC Particles on the Ablation and Mechanical Properties of Carbon/Novolac-Epoxy (EPN1179) Composite at 3000 C°

In this study, the impact of introducing ZrB₂/SiC micro-particles (SiC dominated) with different percentages on the ablation (by means of oxyacetylene test at above 3000 C°) and flexural properties (by three-point bending test) of novolac-epoxy resin was thoroughly investigated. For this reason, 4 samples consisting of Z5S5: 50% ZrB₂ and 50% SiC, Z4S6: 40% ZrB₂ and 60% SiC, Z3S7: 30% ZrB₂ and 70% SiC, Z2S8: 20% ZrB₂ and 80% SiC particles within the novolac-epoxy 1179 matrix were manufactured using the hot press and the mechanical and ablative properties were compared with the pure resin from the backside temperature, weight loss, bending characteristics, and SEM imaging of the ablated regions point of view. The results showed the positive effect of SiC and ZrB₂ additives in reducing the backside sample temperatures up to 63.5% and enhancing bending strength by up to 7% in the 60% SiC and 40% ZrB₂ (Z4S6) sample. In the Z5S5 and Z4S6 samples, the mass ablation rate was improved by 52% and 30.8% respectively. The SEM, EDS, and XRD examinations revealed the formation of essential phases such as SiO₂, ZrO₂, and ZrSiO₄ in the samples following oxyacetylene test.