【摘要】 采用碳纤维复合网胎针刺预制体,制备了液体冲压发动机进气口防护框用复合材料,研究了预制体分层对复合材料构件整体压缩性能的影响。研究结果表明:预制体拐角处制作过程容易起皱及纤维缠绕张力控制不均是导致预制体分层的首要因素。分层的试验件存在局部层间结合力弱以及局部区域存在基体聚集,致使分层处出现裂纹、局部出现破坏,导致整个进气口防护框剩余强度不足而被破坏,试验件的整体抗压强度和轴向位移量均有所降低。为了避免出现针刺预制体分层,提出了在预制体制作过程中控制环向纤维缠绕张力的大小和均匀性,环向铺层针刺时需边压边针刺,并在其完成初步致密化后进行CT检测等改进措施。更多还原

【Abstract】 Carbon fiber needling preform reinforced C/C-SiC composites protectiveframe for the intake of the liquid propellant ramjet was prepared. Effects of delamination of needled preform on integral compressive performance of C/C-SiC protection frame was investigated. The results show that the causes for delamination of needled preform are the wrinkling in corner and disparity of fiber winding tension. The delamination of needled preform can result in poor interlaminal bind force or local SiC aggregation layer and this can seriously affect the residual intensity of C/C-SiC protective frame when the delamination is cracked and damaged,which induces reduction of the integral compressive strength and axial displacement of the component. In order to avoid the delamination of needled preform,the winding tension and uniformity should be controlled and compressing and needling should be used together during the circumferential spreading for the needled preform productive process. Furthermore,CT detection is carried out after needled preform was processed.更多还原