Influence of the electrochemical treatment level of carbon fibers on the compression after impact property of carbon fiber/epoxy composites

• Published in: Polymer composites 2023-02, Vol.44 (2), p.1213-1227
• Main Authors: Chen, Jun, Li, Guanlong, Liu, Zhaobo, Zhong, Xiangyu, Zhao, Yan, Bao, Jianwen
• Format: Article
• Language: English
• Subjects: carbon fiber; Carbon fiber reinforced plastics; Carbon fibers; Chemical activity; composite laminate; compression after impact; Compressive strength; Epoxy resins; Impact tests; Interfacial shear strength; Laminates; Mechanical properties; Photoelectrons; Shear strength; short beam shear strength; Surface energy; Surface properties; Surface roughness; Tensile tests
• ISSN: 0272-8397; 1548-0569
• DOI: 10.1002/pc.27165

In this paper, carbon fibers (CF) with different electrochemical treatment levels were obtained by changing the parameters of electrochemical treatment, and the effect of electrochemical treatment levels on the surface properties of CF was studied by scanning electron microscope, atomic force microscopy and X‐ray photoelectron spectroscopy. The interfacial shear strength (IFSS) of CF with different electrochemical treatment levels were characterized by single fiber‐composite fragmentation. The effects of electrochemical treatment on the mechanical properties of CF were investigated by monofilament tensile test and composite laminate 0° tensile test. Finally, the carbon fibers were compounded with epoxy resin to prepare composite laminates, whose effect on the macroscopic mechanical properties of the composite, such as short beam shear strength (SBSS) and compression after impact (CAI) strength, was studied. As a result, with the increase of the level of electrochemical treatment, the surface roughness and chemical activity of CF increased first and then decreased, while the surface energy shows a gradually increasing trend. The IFSS of CF‐BX shows a gradually increasing trend, while that of the CF‐SX shows a trend of increasing first and then remaining basically unchanged, while SBSS shows the same trend. The monofilament tensile test and composite laminate 0° tensile test showed that the electrochemical treatment did not have a significant effect on the mechanical properties of CF. The compression after impact test showed that with the enhancement of the electrochemical treatment, the CAI of the composite laminates increased first and then remained roughly unchanged.