基于FDM的碳纤维增强聚醚醚酮复合材料低温试验及失效机理  

Low temperature experiment and failure mechanism of carbon fiber reinforced PEEK composites based on FDM

作　　者：崔梦洋 茅健 CUI Mengyang;MAO Jian(School of Mechanical and Automotive Engineering,Shanghai University of Engineering Science,Shanghai 201620,China;Key Laboratory of Intelligent Manufacturing Technology for Large Complex Thin-Walled Components of Aviation in Machinery Industry,Shanghai 201620,China;Shanghai Jiao Tong University Sichuan Research Institute,Chengdu 610213,China)

机构地区：[1]上海工程技术大学机械与汽车工程学院,上海201620 [2]机械工业大型复杂构件智能制造技术重点实验室,上海201620 [3]上海交通大学四川研究院,成都610213

出　　处：《工程塑料应用》2025年第3期153-159,共7页Engineering Plastics Application

基　　金：四川省自然科学基金项目(2023NSFSC0366)。

摘　　要：为研究碳纤维(CF)增强聚醚醚酮(PEEK)复合材料在低温环境下的失效机理,通过熔融沉积成型(FDM)技术制备了CF质量分数为10%的CF/PEEK复合材料试样。设计了5种温度梯度(25,-25,-75,-125,-175℃)下的低温拉伸试验,利用扫描电子显微镜(SEM)对试样断面形貌进行表征,分析了复合材料在不同温度下的力学性能、失效模式及界面性能变化。结果表明,随温度降低,CF/PEEK复合材料的拉伸强度持续下降,在-175℃时达到最低值12.83 MPa,较室温(81.93 MPa)降低了84.3%;而拉伸弹性模量呈现先减小后增大的趋势,在-75℃时最小为6.8 GPa,-175℃时升至最大值7.8 GPa。SEM观察表明,低温环境下复合材料的失效机制包括纤维脆性断裂、基体脆性断裂、纤维-基体界面脱黏及层间分层。其中,-175℃时层间空隙显著增大,表明复合材料界面结合性能严重衰退。PEEK与CF热膨胀系数差异导致界面区域热应力集中,加剧了低温下的界面脱黏;同时,低温抑制了分子链运动,虽增强了基体刚性,但限制了塑性变形能力,最终引发脆性断裂。上述结果揭示了CF/PEEK复合材料在低温下的多尺度失效机制,为该类复合材料的极端环境应用提供了借鉴。To investigate the failure mechanisms of carbon fiber(CF)reinforced polyetheretherketone(PEEK)composites under low-temperature environments,CF/PEEK composite specimens with a carbon fiber mass fraction of 10%were fabricated using fused deposition modeling(FDM)technology.A series of low-temperature tensile tests were conducted under five temperature gradients,including 25,-25,-75,-125,-175℃,and scanning electron microscopy(SEM)was used for characterizing the fracture morphology of the specimens.Then the mechanical properties,failure modes,and interfacial performance change of the composites were analyzed at different temperatures.The results reveal that the tensile strength of CF/PEEK composite decreases continuously with decreasing temperature,reaching a minimum of 12.83 MPa at-175℃,which represents an 84.3%reduction compared to the room-temperature value(81.93 MPa).In contrast,the tensile modulus exhibits a trend of initial decrease followed by increase,with a minimum value of 6.8 GPa at-75℃and a maximum of 7.8 GPa at-175℃.SEM observations indicate that the failure mechanisms of the composites under low-temperature conditions include brittle fracture of fibers,brittle fracture of the matrix,fiber-matrix interfacial debonding,and interlaminar delamination.Notably,at-175℃,the interlaminar gaps become significantly larger,suggesting a severe degradation of interfacial bonding performance of the composite.The mismatch in coefficients of thermal expansion between PEEK and CF can lead to thermal stress concentration at the interface,exacerbating interfacial debonding under lowtemperature conditions.Furthermore,the suppression of molecular chain mobility at low temperatures increases matrix rigidity but limits the plastic deformation capability,ultimately leading to brittle fracture.The above results elucidate the multiscale failure mechanisms of CF/PEEK composites under low-temperature conditions,providing reference for their application in extreme environments.

关 键 词：熔融沉积成型 碳纤维增强聚醚醚酮 低温 失效机理 力学性能 

分 类 号：TB332[一般工业技术—材料科学与工程]