Using carbon-fibre-reinforced polymer (CFRP) composites for electromagnetic interference (EMI) shielding has become a rapidly emerging field. This state-of-the-art review summarises all the recent research advancements in the field of electromagnetic shielding properties of CFRP composites, with exclusive attention paid to experimental work. It focuses on (1) important mechanisms and physical phenomena in the shielding process for anisotropic carbon-fibre composites and (2) shielding performance of CFRP materials as reported in the literature, with important performance-affecting parameters. The key properties which directly influence the shielding performance are identified, the most critical being the carbon-fibre concentration along with length for discontinuous carbon-fibre-filled polymers and the lay-up for continuous carbon-fibre-reinforced composites. The effect of adding conductive inclusions such as metal or carbon nanotubes is also reviewed. It is emphasised that processing conditions are strongly linked with the shielding properties of a composite. This is a first review, which covers all the recent advancements in the field of shielding properties of carbon-fibre-reinforced composites, with detailed analysis of factors influencing these properties and clear distinction between continuous and discontinuous reinforcement. It is shown that CFRP composites make a good candidate as an EMI shielding enclosure material.

Although the investigation of thermal damage in composite materials has increased, the short-term thermal degradation and decomposition mechanisms in a non-oxidative environment have not been well established, as the reported thermal damage results were heavily influenced by the analyses of delicately collected volatiles and the presence of oxygen. The aim of this study, using scanning electron microscopy, Fourier transform infrared spectroscopy and thermogravimetry, along with kinetics, was to develop a post-mortem solid residual-based microscopic characterising methodology for thermal damage in carbon/epoxy composites induced by simulated lightning strikes. Fibre tufting, resin sublimation and discolouration were found to represent the severity of damage in three damage zones. Whilst fibre tufting was caused not by thermal sublimation but by returning shock waves, resin sublimation and discolouration were dominated by Joule heating. The carbon concentration in the damaged zones was found to radially decrease outwards and vice versa with oxygen. Decomposition started from epoxy dehydration, accompanied by discolouration and formation of water and carbonyl, and released chemical compounds like 2-propenal, acetylene and carbonylcontaining aromatic ether. The successful identification of these unique heating-formed functional groups provided the confirmation of the proposed methodology.

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A study on electrical conduction of carbon/epoxy laminates has so far been conducted in an ad hoc nature without a standardised method, involving many extrinsic factors. How these factors affect electrical conduction of carbon/epoxy laminates has not been well established. The objectives of this work are to ascertain the effects of electrical currents, temperatures, and clamping torques on the anisotropic electrical conduction of carbon/epoxy laminates. Two-probe method with solid electrodes was developed with machined carbon/epoxy laminate specimens of various dimensions. The contributions of elevated temperatures and clamping pressures to electrical conduction were investigated. Various contact conditions with or without conductive paint were examined. The relationship of electrical resistance correlating with temperature and clamping pressure was developed to aid an analysis of data trends. From the average test results of 18 groups, aided with qualitative predictions, the milliampere-to-ampere increases of current led to significant reductions in electrical conductivities in both in-plane and through-the-thickness directions. The rises of temperatures resulted in the similar reductions in electrical conductivity due to the increased resistance. The increase in clamping torque increased the electrical conductivity values in both directions. Applying conductive paint to the contact faces did not appear to affect the contact resistance. Thus, the enhanced values of electrical conductivity from the painted specimens were attributed to their lower body temperatures, as the conductive paint at the contact faces soaked up the substantial amount of the electrical energies.