Morphology and anti-ablation properties of composites nozzles under the Φ100mm H2O2- polyethylene hybrid rocket motor test

Environmentally friendly commercial applications spurred us to screen a suitable ablative throat material for the hybrid rocket, while preserving its cost-effective advantages as a special chemical motor. In this research, two types of carbon fiber reinforced composites, i.e. carbon/carbon (C/C) composite and C-f/C-SiC-ZrC composite utilized in high temperature environment, were employed to make the hybrid rocket nozzle. By comparison with the high-density graphite, the anti-ablation properties under the firing environment of Phi 100mm H2O2-polyethylene hybrid rocket motor were characterized. We used whole felt preform to make C/C composite, whose matrix carbon was coming from chemical vapor infiltration of propylene; and the C-f/C-SiC-ZrC composite, which employs the same whole felt preform to make the low-density C/C billet, by infiltrated with Si and Zr organic precursors and pyrolysis at elevated temperatures repeatedly to make the advanced ceramic matrix composite. The firing test lasted 40s for all the candidate materials and the result indicated that the C-f/C-SiC-ZrC composite, whose average linear ablation rate was only 0.003 mm/s, was the most stable one in the firing environment. The SEM images gave detailed morphologies of those nozzle throat materials and proved that the fiber architecture, together with the glassy ceramic oxide, helped the nozzle to withstand the hybrid motor firing environment.

Automated summary

This research aimed to find a suitable ablative throat material for a hybrid rocket while considering environmental factors and cost-effectiveness. Two types of carbon fiber composites were tested, with the C-f/C-SiC-ZrC composite showing the most stable performance with a low ablation rate. Scanning electron microscope images confirmed the effectiveness of the fiber architecture and ceramic oxide in withstanding the firing environment.