【摘要】 将两种颗粒增韧相与HfB2陶瓷基体按配比混料、热压制备了双相颗粒混杂增韧HfB2陶瓷复合材料,重点研究其高温压缩性能、热膨胀性能、耐烧蚀性能以及显微组织。结果表明,HfB2复合材料的室温压缩性能较高,但高温下压缩性能显著下降。随着温度升高,HfB2复合材料的体积膨胀率单调增加;平均线膨胀系数变化平缓;而瞬时线膨胀系数先减小后增大,有一个最小值,最小瞬时线膨胀系数在900℃,其值为5.65×10-6/K。该复合材料在等离子电弧加热器上烧蚀8s后,部分韧化相熔化飞出,留下孔洞。更多还原

【Abstract】 The two-phase particle softening HfB₂ composites were prepared by means of mixing and hot-pressing.Their compressive properties,hot expansion coefficient, ablation resistance and the microstructure were studied.The results showed that the compressive properties of the HfB₂ composites at room temperature were finer,while those at high temperature decreased sharply.With the temperature increased,the volume expansion ratio increased gradually;the average linear expansion factor hardly changed;while the instant linear expansion factor decreased first,and then raised,there was a minimum value.It was 5.65×10^-6/K at 900℃.After the HfB₂ composites had been ablated on the plasma-arc heater for 8s,the partial softening particles of the composites were melted and spurted,remaining holes.更多还原