C/SiC复合材料的常压制备与性能研究

采用聚碳硅烷作为碳化硅先驱体, 以二维0°/90°正交编织碳布叠层后作为增强体, 采用真空压力浸渍的方法制备了C/SiC复合材料, 研究了裂解温度和浆料浓度对复合材料性能的影响. 结果表明: 复合材料的弯曲强度随着裂解温度的升高以及浆料浓度的增加都呈增加趋势; 基体在纤维束内部分布均匀, 但依然有一些小气孔存在; 在1100℃时, 基体中开始生成一定量的β-SiC相, 复合材料的三点弯曲强度达到232MPa, 断裂韧性达到10.50MPa·m^1/2. 在断裂过程中表现出明显的韧性断裂, 断口有较长的纤维拔出.

Pressureless Preparation and Properties of C/SiC Composites

Polycarbosilane was used as the preceramic for matrix formation and 2D layered 0°/90° fabrics as the reinforcement to fabricate C/SiC composites. The effect of pyrolysis temperature and slurry concentration on the properties of the composites was systematically studied. The results show that the flexural stress increase with the increase of both pyrolysis Temperature and slurry concentration. The matrix distribution in fiber bundle is quite homogeneous, but some small pores still exist after eight pyrolysis cycles. When the composite is pyrolyzed at 1100℃, β-SiC begins to form in the matrix. The flexural stress and toughness reach 232MPa and 10.50MPa·m^1/2, respectively. Observation of long pull-out fibers in the fracture surface demonstrates a toughened fracture behavior of the composite.