短切炭纤维对无压烧结ZrB_2-ZrC复合陶瓷性能的影响

Effect of chopped carbon fiber on properties of pressureless sintered ZrB_2-ZrC composite ceramics

以ZrB_2为基体,ZrC和短切高导热炭纤维为增强相,采用无压烧结工艺制备出C-ZrB_2-ZrC复合陶瓷材料,研究炭纤维添加量、烧结温度对C-ZrB_2-ZrC复合陶瓷材料致密度、抗烧蚀性能、热导率以及显微组织结构的影响。试样致密度最高可达95.5%、开孔率最低为0.5%、热导率最高为129 W/(m·℃)、质量烧蚀损失率最小为2.9×10^(-5) g/s,线烧蚀率最小为4.2×10^(-5) mm/s。研究结果表明,高导热炭纤维的加入能促进复合陶瓷材料的致密化,增强复合陶瓷材料的热导性能以及抗烧蚀性能。

ZrB2-ZrC composite ceramics were prepared by pressureless sintering process,using zirconium diboride(ZrB2) as the matrix, and zirconium carbide(ZrC) and chopped high thermal conductivity carbon fiber as the reinforcing phase. The effects of the content of carbon fiber and sintering temperatures on the density,ablation resistance,thermal conductivity and microstructure of CZrB2-ZrC composite ceramic materials were studied. The sample was obtained with the compactness of up to 95.5%,the minimum aperture ratio of 0.5%,and the thermal conductive of up to 129 W/(m·℃). The minimum mass ablation loss rate is 2.9×10-5g/s, and the minimum line ablation loss rate is 4.2×10-5mm/s. The results showed that the addition of high thermal conductivity carbon fiber can promote the densification of the composite ceramic materials and enhance the thermal conductivity,as well as anti-ablative performance of the prepared composite materials.