Enhancement of fracture toughness of hierarchical carbon fiber composites via improved adhesion between carbon nanotubes and carbon fibers. (April 2015)

• Record Type: Journal Article
• Authors: Kim, Hansang; Oh, Eugene; Hahn, H. Thomas; Lee, Kun-Hong
• Is Part Of: Composites. Volume 71(2015)
• Page Start: 72
• Page End: 83
• Publication Date: 2015-04
• Subjects: ALD atomic layer deposition -- ASTM American Society for Testing and Materials -- CNT carbon nanotube -- CF carbon Fiber -- COD crack opening displacement -- CVD chemical vapor deposition -- DCB double cantilever beam -- GIC critical strain energy release rate -- GIC-init critical strain energy release rate at initiation -- LP-CVD low pressure chemical vapor deposition -- sccm standard cubic centimeter per minute -- UD unidirectional -- VARTM vacuum assisted resin transfer molding; A. Carbon fiber -- A. Hybrid -- A. Nano-structures -- B. Fracture toughness; Composite materials -- Periodicals; Manufacturing processes -- Periodicals; Composite materials; Manufacturing processes; Periodicals; 620.11805
• DOI: 10.1016/j.compositesa.2014.12.014
• Languages: English
• ISSNs: 1359-835X

Abstract

Abstract: Hierarchical +1 composites consisting of carbon fibers with carbon nanotubes (CNTs) grown onto them and an epoxy matrix were processed, and the mode I fracture toughness of these composites was evaluated. The mode I fracture toughness of the initial batches of the hierarchical composites was lower than that of the baseline samples without CNTs. Hence, efforts to enhance the adhesion between carbon fibers and CNTs were made, resulting in enhanced adhesion. The enhanced adhesion was confirmed by Scotch tape tests and mode I fracture toughness tests followed by fractographic studies. The mode I fracture toughness of the hierarchical composites with enhanced adhesion was 51% and 89% higher than those of the baseline samples and hierarchical composites with poor adhesion, respectively. Moreover, fractographic studies of the fracture surfaces of the hierarchical composites with enhanced adhesion showed that CNTs were still attached to carbon fibers even after the mechanical tests.