PIP工艺对2DC／SiC-ZrB2复合材料结构和力学性能的影响

Effect of PIP Process on Microstructure and Mechanical Properties of 2D C/SiC-ZrB_2 Composites

采用CVI结合SI及PIP工艺制备2D C/SiC-ZrB2复合材料。研究了PIP工艺中循环浸渍次数及热处理对复合材料结构和力学性能的影响。比较了多孔C/SiC浸渍浆料后用PIP结合CVI致密化和仅用CVI致密化的效果。结果表明:浸渍裂解后,热处理温度相同,热处理次数对复合材料的开孔率和弯曲强度影响不大。2D C/SiC-ZrB2复合材料的弯曲强度不随PIP次数的增多而增加,PIP处理二次后,复合材料的强度逐渐增加,PIP处理五次,强度达到最大值,制备的复合材料开孔率为8.0%、弯曲强度为423 MPa。SI后用PIP结合CVI致密化比仅用CVI致密化效果好。

2D C/SiC-ZrB2 composites were fabricated by combining chemical vapor infiltration, slurry infiltration and polymer infiltration and pyrolysis （PIP） process. Effects of PIP cycle number and heat-treatment on the microstructure and mechanical properties of the C/SiC-ZrB2 were investigated. Two densification processes were compared： PIP combining with CVI and by using CVI alone on porous C/SiC infiltrated slurry. The results indicated that, at the same heat treatment temperature, the times of heat treatment had little effect on the open porosity and flexural strength. The flexural strength increased nonlinearly with increasing PIP cycles. After twice PIP processes, the flexural strength of the composite increased, and reached its maximum value at the fifth PIP cycle. The open porosity and flexural strength of the composite fabricated by 5 times PIP are 8.0% and 423 MPa, respectively. After slurry infiltration, this hybrid process of PIP and CVI is more suitable to densifieation of the composite than single CVI process.