Improving the delamination resistance of carbon fiber/epoxy composites by brushing and abrading of the woven fabrics

Improved Interlaminar Fracture Toughness and Electrical Conductivity of CFRPs with Non-Woven Carbon Tissue Interleaves Composed of Fibers with Different Lengths

“…The CFRPs laminates composites were fabricated from 16 plies of plain-woven carbon fibers and neat epoxy by the hand lay-up method used before [29]. A 0.2 mm thick Kapton polyimide film and the prepared NWCT were inserted at the mid-plane of the laminates to serve as the pre-crack and interleave respectively to fabricate the sample for the interlaminar fracture toughness tests, illustrated as Figure 2.…”

“…In contrast to the case of the Mode I fracture toughness, as summarized in Table 2, interleaves composed of carbon fibers with longer length such as NWCT tissue (15 mm), CNTs grated NWCT (15 mm) and carbon nanofibers exhibit better effect on the Mode II fracture toughness improvement than our NWCT interleave with shorter fiber length (0.8 and 4.3 mm), indicating that the NWCTs made of longer fibers can improve Mode II fracture toughness more effectively than those made of shorter fibers. To put the Mode I toughness results obtained in this work in perspective of similar studies by other researchers, relevant toughness data was compiled from the literature in Table 1 for easy comparison, in which the Mode I interlaminar fracture toughness for CFRP composites was modified by various carbon materials such as NWCT tissue with longer fiber length (15 mm) [20,25], CNTs grafted NWCT [26], carbon nanofibers [11] and brushing and abrading carbon fibers [29]. Since all materials have different CFRPs types and fiber content, it is more sensible to compare the percent increase of the plateau toughness relative to that of neat CFRPs as the baseline.…”

Building Hierarchical Micro-Structure on the Carbon Fabrics to Improve Their Reinforcing Effect in the CFRP Composites

“…The preparation, multi-functionality and application of ZnO nanowire-carbon fiber hybrid materials were mainly investigated in most previous studies, and few efforts were made to characterize the mechanical properties of this hybrid material. Actually, the mechanical properties, particularly, CNT-SCF tissue DCB 98-125 [18] CNT forests by flame DCB 67 [13] CNT forests by CVD DCB 31-61 [10] CFF by brushing method DCB 62.4 [32] the interfacial adhesion strength between the carbon fiber and ZnO NWs, play a key role in their application. For example, the ZnO NWs may easily fall off the carbon fiber in service if the interfacial adhesion between carbon fibers and ZnO NWs is relatively weak, which may lead to degradation of the material performance and possible material failure in further.…”

“…It can be concluded that both mode I and mode II interlaminar toughness of CF/ZnO NWs laminates were indeed found to be increased, and further increases in these toughness values were achieved for the CF/PDA/ZnO NWs hybrid laminates due to the enhanced interfacial interaction between ZnO NWs and PDA-modified CF. Table 4 gives existing results on the mode I and mode II interlaminar fracture toughness for CFRP composites modified by various hierarchical reinforcement such as ZnO NWs [26], SCF tissue [18], CNT-SCF tissue [18], CNT forests by flame [13] and CFF by brushing method [32]. It is noticed that the interlaminar fracture toughness of composites laminate with ZnO NWs is lower than composites laminate with carbon reinforcement.…”

“…The surface morphology of (a) original carbon fabric; (b) carbon fabric abraded by 5 times; and (c) carbon fabric abraded by 30 times[32].…”