2D Plain and 3D Needle-punched C/SiC Composites:Low-velocity Impact Damage Behavior and Failure Mechanism  

2D平纹和3D针刺C/SiC复合材料的低速冲击破坏行为和失效机理

作　　者：LUAN Xingang HE Dianwei TU Jianyong CHENG Laifei 栾新刚;何典蔚;涂建勇;成来飞(西北工业大学超高温结构复合材料重点实验室,西安710072;西安金山瓷业有限公司,西安710118)

机构地区：[1]Science and Technology on Thermostructural Composite Materials Laboratory,Northwestern Polytechnical University,Xi’an 710072,China [2]Xi’an Golden Mountain Ceramic Composites Co.,Ltd.,Xi’an 710118,China

出　　处：《无机材料学报》2025年第2期205-214,I0004,共11页Journal of Inorganic Materials

基　　金：Aeronautical Science Foundation of China(2021Z057053001)。

摘　　要：Continuous carbon fiber reinforced silicon carbide(C/SiC)composites are often subjected to low-velocity impacts when utilized as structural materials for thermal protection.However,research on in-plane impact damage and multiple impact damage of C/SiC composites is limited.To investigate the in-plane impact damage behavior of C/SiC composites,a drop-weight impact test method was developed for strip samples,and these results were subsequently compared with those of C/SiC composite plates.Results show that the in-plane impact behavior of C/SiC strip samples is similar to that of C/SiC composite plates.Variation of the impact load with displacement is characterized by three stages:a nearly linear stage,a severe load drop stage,and a rebound stage where displacement occurs after the impact energy exceeds its peak value.Impact damage behavior under single and multiple impacts on 2D plain and 3D needled C/SiC composites was investigated at different impact energies and durations.Crack propagation in C/SiC composites was studied by computerized tomography(CT)technique.In the 2D plain C/SiC composite,load propagation between layers is hindered during impact,leading to delamination and 90°fiber brittle fracture.The crack length perpendicular to the impact direction increases with impact energy increases,resulting in more serious 0°fiber fracture and a larger area of fiber loss.In the 3D needled C/SiC composite,load propagates between the layers during impact through the connection of needled fibers.The fibers continue to provide substantial structural support,with notable instances of fiber pull-off and debonding.Consequently,the impact resistance is superior to that of 2D plain C/SiC composite.When the 3D needled C/SiC composite undergoes two successive impacts of 1.5 J,the energy absorption efficiency of the second impact is significantly lower,accompanied by a smaller impact displacement.Moreover,the total energy absorption efficiency of these two impacts of 1.5 J is lower than that of a single 3.0 J impact.连续碳纤维增强碳化硅(C/SiC)复合材料用作热防护结构材料时,可能遭受低速冲击损伤。然而,目前对于C/SiC复合材料面内冲击损伤和多次冲击损伤的研究尚不充分。本研究通过落锤冲击试验,测试了C/SiC条状试样的面内冲击破坏行为,并与C/SiC复合板的落锤冲击试验进行了比较。结果表明,C/SiC条状试样的面内冲击行为与C/SiC复合板相似,冲击载荷随位移的变化可分为三个阶段:近似线性阶段、载荷骤降阶段、冲击能量超过峰值后试样位移发生反弹阶段。对二维(2D)平纹C/SiC复合材料和三维(3D)针刺C/SiC复合材料在不同冲击能量和时间下的单次和多次冲击破坏行为进行了研究。借助计算机断层扫描(CT)技术研究了C/SiC复合材料的裂纹扩展。对于2D平纹C/SiC复合材料,冲击过程中载荷难以在预制体的层间传播,导致分层和90°纤维脆性断裂。随着冲击能量增大,垂直于冲击方向的裂纹长度增加,0°纤维断裂加剧,纤维损失面积增大。对于3D针刺C/SiC复合材料,冲击过程中载荷通过针刺纤维的连接在层间传播,纤维依然起到良好的支撑作用,出现纤维拉断和脱黏现象,其抗冲击性能优于2D平纹C/SiC复合材料。对于受到两次1.5 J冲击的3D针刺C/SiC复合材料,第二次冲击的能量吸收率明显降低,冲击位移减小,两次1.5 J冲击的总能量吸收效率低于单次3.0 J冲击。

关 键 词：ceramic-matrix composite FRACTURE low-velocity impact computerized tomography analysis 

分 类 号：TB332[一般工业技术—材料科学与工程]