The effect of fibre content on properties of ceramifiable composites

Abstract

With the development of rocket and aerospace technology in recent decades, people have put forward higher requirements on the heat resistance and ablation performance of thermal protection materials. In this paper, zirconia fibre hybrid alumina fibre/boron phenolic (ZA/BPF) ceramifiable composites, based on ceramic fillers of MgO, Al₂O₃, SiC and mica-modified boron phenolic resin matrix, were prepared with different hybrid fibre contents (5, 10, 15, 20, 25, 30 wt-%) by hot compression moulding. The result shows that fibre contents have little effect on the ablation resistance of composite materials which all have a low linear ablation rate below 0. 01 mm s⁻¹. When the fiber content is 25%, the ZA/BPF composite reaches the highest bending strength 48. 86 MPa and 15. 57 MPa before and after sintering respectively. It is showed by the SEM results that too high and too low fibre content would both lead to poor bonding between resin and fibre interfaces.