Influence of Reinforcement Structures and Hybrid Types on Inter-Laminar Shear Performance of Carbon-Glass Hybrid Fibers/Bismaleimide Composites under Long-Term Thermo-Oxidative Aging

Abstract

The effects of reinforcement structures and hybrid types on the inter-laminar shear strength (ILSS) of carbon-glass hybrid fibers/bismaleimide composites under thermo-oxidative aging conditions were investigated. The process resulted in progressive deterioration of the matrix and fiber/matrix interfaces, in the form of chain scissions, weight loss, and fiber/matrix debonding, which significantly led to the decrease of the ILSS of composites. Moreover, the three-dimensional orthogonal woven hybrid composites (3D composites) showed higher ILSS retention rate than those of the laminated orthogonal hybrid composites (laminated composites). No delamination occurred in the aged 3D composites like in the aged laminated composites. This was because the Z-binder yarns in the 3D composites resisted the inter-laminar shear load, although the resin was damaged and the adhesive force between fiber bundles and resin decreased seriously after thermo-oxidative aging. Meanwhile, the ILSS retention rate of the laminated composites with the carbon fiber as intermediate layers was higher than that of the laminated composites with the glass fiber as the intermediate layers. This was because the carbon fiber/bismaleimide interface bonding performance was stronger than that of the glass fiber/bismaleimide at the same thermo-oxidative aging condition.

Hardness and flexural performance of 3D orthogonal carbon/glass fibers hybrid composites under thermal-oxidative aging

“…Bin Yang et al [15] reported that the combination of CF and GF in epoxy resin enhanced the mechanical performance of the resulting composites at high temperatures. Our previous study [16] also confirmed that the CF/BMI interfacial bonding was stronger than GF/BMI at the same TOA condition. Thus, understanding the effect of TOA on the performance of hybrid composites has become vital for the effective design of hybrid composite materials.…”

“…On increasing the aging time, map cracking can be observed in Figure 6(c) and (d). The observed phenomenon can be attributed to the severe degradation of the resin, revealed in our previous study [16]. Owing to the breaking of the chains in BMI resin, the resulting shrinkage and mass loss induce the initiation of small cracks.…”

“…Overall, the findings from TGA confirm the excellent thermal stability of the BMI resin at the high-temperature condition for a short time. However, it is vital to investigate the state of the BMI resin after long-term TOA analysis at 250 C. For this, FTIR analysis has been carried out on the original and aged samples in our previous study [16]. The FTIR results indicate that the chemical changes in the aged samples are caused by decomposition.…”

“…Similar to the flexural strength, the flexural modulus decreased on increasing the aging time. After long-term TOA, the chemical structure of the BMI resin is observed to be destroyed [16], leading to a reduction in the stiffness of the composites. Therefore, the load-bearing capacity of the 3 D-CF/GF/VMI composites is weakened.…”

Enhancement of Thermal and Mechanical Properties of Bismaleimide Using a Graphene Oxide Modified by Epoxy Silane

“…When the material receives impact, the cross-linked network structure will tend to help the resin matrix to bear the external force and conduct the force to the GO through the molecular chain, so as to achieve the purpose of toughening the resin matrix [ 38 , 39 ]. Recently, there has been more focus on incorporation of GO into BMI networks [ 40 , 41 , 42 , 43 , 44 , 45 ]. However, scarce literature focused on improving toughness while improving thermomechanical properties has been reported.…”