【摘要】 将SiC晶须与ZrB2基体原料按配比混料,然后热压制备了晶须增韧ZrB2基超高温陶瓷复合材料,研究了复合材料的性能与显微组织。结果表明,所制备的ZrB2复合材料密度较高,其相对密度为98.5%。复合材料的断裂韧性比较低,其平均值为1.95MPa·#m。在等离子电弧加热器上烧蚀9s钟不碎裂;其质量损失随烧蚀时间延长而增加,两者之间近似呈平方关系。复合材料热压坯的组织为晶粒尺寸相近、成分均匀的组织,在等离子电弧加热器上烧蚀5s钟后,部分韧化相开始熔化飞出,留下孔洞。更多还原

【Abstract】 The ZrB2-SiCw ultrahigh temperature ceramics were prepared by means of mixing and hot-pressing,and the prope-rties and microstructure were studied.The results showed that the densities of the ZrB2 composites were high,and their relati-ve densities exceed 98.5% of the theory density.Their fracture toughness was low,and the mean value was equal to 1.95 MPa·■.The ZrB2-SiCw composites did not rupture after they had been burned on the plasma-arc heater for 9 seconds.The mass loss increased with the elongation of ablation time,which exhibited square relationships approximately.After the ZrB2 composites with the microstructure of equal grains and uniform component have been burned on the plasma-arc heater for 5 seconds,the partial softening phase of the ZrB2 composites starts melting and spurting,thus holes remaining.更多还原