新型炭纤维/泡沫炭预制体的制备及致密化研究

由炭纤维/酚醛树脂经过发泡、固化和炭化制备出4种不同炭纤维含量(3%,7%,10%和15%)的泡沫炭作为制备炭/炭复合材料新型预制体,通过等温化学气相沉积对预制体进行致密化处理。研究了炭纤维含量对预制体微观结构、致密化过程及力学性能的影响。结果表明:炭纤维含量增加,使预制体产生更多的微裂纹,并有更多的炭纤维裸露在泡沫炭韧带外,有助于提高化学气相沉积的沉积速率。炭纤维/泡沫炭预制体炭/炭复合材料压缩强度随着预制体中炭纤维含量的增加而增加,当炭纤维体积分数为10%时,压缩强度达到峰值,为43MPa。

STUDY ON PREPARATION AND DENSIFICATION OF CARBON FIBER/CARBON FOAM PREFORM

Four kinds of carbon foam containing 3%,7%,10%and 15?rbon fibers,prepared from carbon fibers and phenolic resin via foaming,solidifying and carbonization processes were used as the preforms of C/C composites,and densified with isothermal chemical vapor infiltration.The Effects of carbon fiber content on microstructure of preform,densification and mechanical properties of C/C composites were investigated.The results showed that increase of carbon fiber content made the preform generate more micro-cracks and more carbon fibers are outside the ligament,and it could improve the deposition rate of chemical vapor infiltration.With the increase of the content of carbon fibers,the compressive strength was enhanced.When the volume fraction of carbon fibers was 10%,the values of compressive strength reached the peak of 43 MPa.