The mechanical properties of epoxy resin can be enhanced by adding nanofillers into its matrix. This study researches and compares the impacts of adding nanofillers with different dimensions, including two-dimensional boron nitride and zero-dimensional silica, on the mechanical and toughness properties of epoxy resin. At low fractions (0–2.0 wt%), 2DBN/epoxy composites have a higher Young’s modulus, fracture toughness and critical strain energy release rate compared to SiO₂/epoxy composites. However, the workability deteriorated drastically for BN/epoxy composites above a specific nanofiller concentration (2.0–3.0 wt%). BN prevents crack growth by drawing and bridging. SiO₂ enhances performance by deflecting the crack direction and forming voids. Additionally, the dimension and content of nanofiller also influence glass transition temperature and storage modulus significantly.

Multi-walled carbon nanotubes (MWCNTs) in the form of “forests” were synthesized directly on the surface of stainless steel (SS) mesh from ethanol flame volume. The growth dependence of the MWCNT forests on the porosity of SS mesh substrate and the morphologies and growth mechanism of the MWCNT forests were investigated in detail by a combination of turbulent flow simulation, scanning electron microscopy (SEM), transmission electron microscope (TEM), and Raman and X-ray diffraction (XRD) spectroscopy. The growth height of the MWCNT forests exhibited a strong dependence on the flame gas flow rate controlled by the porosity of SS mesh substrate, and the maximum averaged height of the MWCNT forests reached 34 μm. Most MWCNTs grew perpendicularly on the surface of SS wires, and some branch, welded, and spiral structures were observed by SEM and TEM. The MWCNT-decorated mesh was used as a novel heating element to weld glass-fabric-reinforced polyetherimide (GF/PEI) thermoplastics. We found that the maximum tensile lap-shear strength (LSS) of the welded joints could reach 39.21 MPa, an increase of 41% in comparison with that of conventional SS mesh-based joints.

Although graphene has been widely used as a nano-filler to enhance the conductivity of porous materials, it is still an unsatisfactory requirement to prepare graphene-based sponge porous materials by simple and low-cost methods to enhance their mechanical properties and make them have good sensing and capacitive properties. Graphene platelets (GnPs) were prepared by the thermal expansion method. Graphene-based sponge porous materials were prepared by a simple method. A flexible sensor was formed and supercapacitors were assembled. Compared with other graphene-based composites, the graphene-based composite sponge has good electrical response under bending and torsion loading. Under 180° bending and torsion loading, the maximum resistance change rate can reach 13.9% and 52.5%, respectively. The linearity under tension is 0.01. The mechanical properties and capacitance properties of the sponge nanocomposites were optimized when the filler fraction was 1.43 wt.%. The tensile strength was 0.236 MPa and capacitance was 21.4 F/g. In cycles, the capacitance retention rate is 94.45%. The experimental results show that the graphene-based sponge porous material can be used as a multifunctional flexible sensor and supercapacitor, and it is a promising and multifunctional porous nanocomposite material.

As high-performance and lightweight materials, such as aluminum alloy and titanium alloy, metals are still used in aerospace and aircraft industry. Therefore, the bonding process of composite materials and metals is one of the key issues to be urgently solved and developed in the aerospace industry. Therefore, the connection technology of CFRP to metal is reviewed in this paper. The implementation process of laser welding, friction welding and resistance welding and the types of connection materials are summarized.

Two types of T800 grade carbon fibers, produced using distinct spinning processes, were utilized to fabricate thermoplastic prepregs via the hot melt method. These prepregs were subsequently employed to produce thermoplastic composites. A universal testing machine was used to assess the tensile, bending, and interlaminar shear properties of the composites, evaluating the impact of the two different spinning processes on their mechanical characteristics. The experimental results indicate that the dry spray wet spinning carbon fiber (T800-DJWS) exhibits a smoother surface, more regular cross-section, and more uniform distribution compared to the wet spinning carbon fiber (T800-WS), enhancing the prepreg preparation via the hot melt method. The T800-DJWS/PAEK composite demonstrates a tensile strength that is 706 MPa higher than the T800-WS/PAEK composite, while the latter exhibits a bending modulus 31 GPa higher than the former.