取向碳纳米管纤维纱插层碳纤维/环氧树脂复合材料的层间性能及增韧机制  

Interlaminar properties and toughening mechanisms of aligned carbon nanotube fiber veil interleaved carbon fiber/epoxy composites

作　　者：吴龙强 欧云福 茅东升[2] 祝令状 刘立起 李赫[2] WU Longqiang;OU Yunfu;MAO Dongsheng;ZHU Lingzhuang;LIU Liqi;LI He(School of Material Science and Engineering,Shanghai University,Shanghai 200444,China;Ningbo Institute of Materials Technology and Engineering,Chinese Academy of Sciences,Ningbo 315201,China)

机构地区：[1]上海大学材料科学与工程学院,上海200444 [2]中国科学院宁波材料工程与技术研究所,宁波315201

出　　处：《复合材料学报》2023年第10期5611-5620,共10页Acta Materiae Compositae Sinica

基　　金：宁波市自然科学基金(2021J208);中国博士后科学基金(2022M713241);中科院“百人计划”(2021R01005);宁波市“甬江引才工程”(2021A-045-C)。

摘　　要：碳纤维增强树脂基复合材料(CFRP)由于比强度高、比模量高等优异性能应用广泛,但受层状结构特性和环氧树脂本征脆性影响,其沿厚度方面的力学性能较差,在遭受面外冲击和面内压缩载荷下容易发生分层,进而降低复合材料强度,因此提高该复合材料的层间断裂韧性尤为重要。本文通过在复合材料层间区域引入高度取向的碳纳米管(CNT)纤维纱来提升其层间断裂韧性。为确保纤维纱被树脂充分浸润,首先将其浸泡于经丙酮稀释的环氧树脂溶液中,待丙酮挥发后,将之插层于自制碳纤维预浸料的层间区域,随后借助热压工艺固化成型。通过ASTM标准对增韧样品的I型和II型层间断裂韧性进行了评估,并结合横截面的光学显微观察和断裂面的扫描电镜分析,清晰地显示了裂纹的扩展路径,并揭示了CNT纤维纱的层间增韧机制。结果表明:CNT纤维纱增韧样品的I型和II型层间断裂韧性分别提高37.4%和41.8%。其增韧机制主要包括增韧树脂、加强碳纤维桥接及引发裂纹偏转等。Carbon fiber reinforced polymer(CFRP)composites are widely used because of their excellent properties such as high specific strength and high specific modulus,but their mechanical properties along the thickness are poor due to the laminar structure characteristics and the intrinsic brittleness of epoxy resin,and they are prone to delamination under out-of-plane impact and in-plane compression loads,which in turn reduce the strength of the composites.Therefore it is especially important to improve the interlaminar fracture toughness of the composites.In this paper,we attempt to improve the interlaminar fracture toughness of the composite by introducing highly oriented carbon nanotube(CNT)fiber veils in the interlaminar region.To ensure that the fiber veils are well infiltrated by the resin,they are first immersed in an epoxy resin solution diluted with acetone.After the acetone evaporated,it is inserted into the interlayer region of the homemade carbon fiber prepreg and subsequently cured by a hot pressing process.The mode I and mode II interlaminar fracture toughness of the toughened samples are evaluated via ASTM testing standards.Combined with the optical microscopic observation of the cross-section and scanning electron microscopy analysis of the fracture surface,the crack propagation paths are clearly shown and the interlaminar toughening mechanisms of CNT fiber veils are revealed.The results show that the mode I and mode II interlaminar fracture toughness of CNT veil toughened samples are improved by 37.4%and 41.8%,respectively.The toughening mechanisms mainly include matrix toughening,strengthening carbon fiber bridging and crack deflection.

关 键 词：碳纳米管纤维纱 层间增韧 纤维桥接 裂纹偏转 碳纤维增强树脂基复合材料 

分 类 号：TB332[一般工业技术—材料科学与工程]