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Novel hybrid thermal protection material (TPM), consisting of TaSi 2 -based coating on carbon-bonded fiber (CBCF) composites and mullite fiber insulation tiles, is investigated using a plasma wind tunnel. Mullite fiber insulation tile is ceramically bonded to coated-CBCF composites. Results show that surface temperatures range from 400 °C°C to 1200 °C°C at low heat flux and dynamic pressure. However, at high heat flux and dynamic pressure, the surface temperature rapidly reaches 1400 °C°C, and the damage to the TaSi 2 -based coating is also observed. The cold-wall temperature of the hybrid structure remains at room temperature during ablation. In addition, TPM is invalid because of the consumption of the TaSi 2 -based coating. [ABSTRACT FROM AUTHOR]

As a typical kind of multiple flaws, collinear flaws are particularly detrimental to the mechanical properties of ceramics. Here, two identical collinear micron-sized flaws with controllable length and spacing were successfully fabricated in ZrB 2 -20 vol% SiC (ZS) ceramic using femtosecond laser, and the effect of flaw length and spacing on flexural strength as well as fracture behavior (i.e., load-displacement curve and fractography) of ZS ceramic were investigated. The flexural strength almost remained constant when the flaw spacing was less than the critical value, which strongly depended on the flaw length, then increased gradually with increasing flaw spacing and reached a plateau. If the ratio between flaw spacing and flaw length was small enough, flaws would tend to coalescence first before fracture, owing to the strong interaction between flaws. If the ratio was too large, the center of the mirror area in fracture surface would be offset. [ABSTRACT FROM AUTHOR]