Ablation resistance of ZrB2-SiC-AlN ceramic composites

ZrB2-20 vol.%SiC-5 vol.%AlN ceramic composites (ZSA) were fabricated by hot pressing sintering under inert gas protected, which mechanical properties were improved obviously by introducing AlN as sintering aid. Ablation tests of ZSA were conducted with different heat flux parameters in high frequency plasma wind tunnel. The results showed that ZSA exhibited excellent ablation resistance at 2000 degrees C for 300 s in oxidation environment and a dense coherent scale was formed after ablation, whereas a strong degradation and mass loss were observed at 2600 degrees C for 300 s. The ablation behavior, microstructures evolvement and the effect of AlN were analyzed. (C) 2008 Elsevier B.V. All rights reserved.