摘要
本文通过自主搭建超低温/室温循环研究平台,探究了超低温浸泡时间和超低温/室温循环次数对碳纤维/环氧树脂(CF/EP)复合材料各项力学性能的影响。之后将不同面密度共聚尼龙纤维网纱(PAV)插入到复合材料层间,研究在液氮中超低温浸泡16 h后复合材料层间韧性的变化。结果表明,未增韧情况下超低温浸泡16 h后CF/EP复合材料的Ⅰ型层间断裂韧性(G_(ⅠC))、Ⅱ型层间断裂韧性(G_(ⅡC))、拉伸强度和弯曲强度分别下降了46.2%、22.9%、17.7%和3.2%。而当插入面密度为8 g/m^(2)的PAV时,与未增韧样相比CF/EP复合材料的G_(ⅠC)在室温下和超低温浸泡16 h后分别提升了49.1%和114.0%;当插入面密度为24 g/m^(2)的PAV时,增韧样的G_(ⅡC)相比于未增韧样在室温下和超低温浸泡16 h后分别提升了140.2%和178.0%。此外PAV的插入并未对CF/EP复合材料的弯曲性能和层间剪切强度造成明显影响。研究表明,PAV的增韧机制主要是尼龙树脂的拔出、基体塑性形变以及引发裂纹的偏转。本研究改善了超低温处理后的CF/EP复合材料层间韧性,对推动超低温贮箱复合材料化进程具有积极意义。
In this paper,a research platform for cryogenic/room temperature cycles was built to explore the effects of cryogenic immersion time and cryogenic/room temperature cycle times on the mechanical properties of carbon fiber/epoxy(CF/EP)composites.Then,copolymerized nylon fiber veil(PAV)with different areal densities was inserted into the interlaminar of the composites,and the interlaminar toughness of the composites was studied after 16 h of cryogenic immersion in liquid nitrogen.The results demonstrate that the interlaminar fracture toughness of mode Ⅰ(G_(ⅠC)),mode Ⅱ(G_(ⅡC)),tensile strength and flexural strength of CF/EP composites decline by 46.2%,22.9%,17.7%and 3.2%,after 16 h of cryogenic immersion without toughening.The G_(ⅠC)of CF/EP composites is increased by 49.1%and 114.0%at room temperature and after 16 h of cryogenic immersion,respectively,when PAV with 8 g/m^(2)areal densities were inserted.The G_(ⅡC)is increased by 140.2%and 178.0%at room temperature and after 16 h of cryogenic immersion,when PAV with 24 g/m^(2)areal densities were inserted.In addition,the insertion of PAV didn't significantly affect the flexural properties and interlaminar shear strength of CF/EP composites.Our findings suggest that the toughening mechanism of PAV is mainly the pull-out of nylon resin,plastic deformation of matrix,and the deflection of initiating cracks.This study improves the interlayer toughness of CF/EP composites after cryogenic treatment,which is of positive significance for promoting the compositing process of cryogenic fuel tanks.
作者
曹楠
张辉
刘千立
薛怿
阳泽濠
杨晨曦
刘杰
韩克清
马禹
CAO Nan;ZHANG Hui;LIU Qianli;XUE Yi;YANG Zehao;YANG Chenxi;LIU Jie;HAN Keqing;MA Yu(State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,College of Materials Science and Engineering,Donghua University,Shanghai 201620,China;Center for Civil Aviation Composites,Donghua University,Shanghai 201620,China;Shanghai Key Laboratory of Lightweight Composite,Donghua University,Shanghai 201620,China)
出处
《复合材料学报》
北大核心
2025年第7期3756-3766,共11页
Acta Materiae Compositae Sinica
基金
上海市科委(22511102702)
国家重点研发计划(2022YFB3709202)
江苏省重点研发计划(BE2021014-3)。
关键词
复合材料
层间增韧
超低温处理
力学性能
共聚尼龙纤维网纱
composites
interlayer toughening
cryogenic immersion
mechanical property
nylon copolymer fiber veil
