Maximizing Electromagnetic Interference Shielding Through Carbon Fiber Plating with Nickel: A Parameter-Based Approach

Electromagnetic interference (EMI) poses significant challenges to modern electronic systems and devices, garnering increasing attention as technology advances. EMI shielding methods have emerged as a crucial solution to mitigate the associated problems. The primary objective of shielding is to deflect or absorb electromagnetic waves emitted from a source. Traditionally, metals have been used for shielding materials due to their excellent conductivity. However, the high weight and cost of metals have spurred research into alternative materials. Carbon fiber materials have gained prominence in recent years due to their exceptional mechanical and electrical properties. These materials find diverse applications across industries, including defense, automotive, aviation and space. One approach to enhance the conductivity of carbon fibers is the application of metallic coatings. This study investigates the electromagnetic shielding properties of nickel-coated and uncoated polyacrylonitrile-based (PAN-based) carbon fiber fabrics at the frequency ranges of "300-1500 MHz," "2170-3300 MHz" and "3300-4900 MHz" offering valuable insights into their applications. Additionally, microstructure analysis and energy-dispersive X-ray spectroscopy (EDS) were conducted. The results demonstrated that nickel coating significantly improves EMI shielding effectiveness within the specified frequency ranges. Notably, the Ni-electroplated sample, treated at a current density of 8.7 A/dm2 for 30 min, exhibited the highest shielding effectiveness at "300-1500 MHz." Moreover, the most noteworthy performance was observed in electroless nickel-coated carbon and nickel-electroplated (at a current density of 7.3 A/dm2 for 45 min) fiber specimens within the "2170-3300 MHz" and "3300-4900 MHz" frequency ranges. Absorption and reflection values were calculated to clarify the underlying mechanisms governing EMI shielding behavior. The findings reveal that absorption mechanisms predominantly contribute to the observed EMI shielding behavior.