MECHANICAL AND ABLATION PROPERTIES OF ULTRA-HIGH TEMPERATURE COMPOSITES WITH A VARIABLE MATRIX-COMPOSITION

摘要

In order to lessen the weight and improve the ablation resistance of thermal protecting materials, an ultra-high temperature composite reinforced by carbon fibers with a variable matrix-composition was fabricated by a slurry infiltration (SI) technique and an isothermal chemical vapor infiltration (ICVI) densification process. In this composite, one side was the carbon fiber reinforced C- ZrB_2-SiC matrix composite from the surface to a 2-3mm depth, and the other side was the carbon fiber reinforced C-SiC matrix composite. The flexural strength and modulus of the composites are 260 MPa and 19.2 GPa, respectively. Due to the addition of ZrB_2 particles, the composites exhibit a good anti-ablation property at 1900±100 °C with a linear ablation rate of 1.11 × 10~(-3) mm/s.