Electromagnetic interference shielding properties of carbonyl iron powder-carbon fiber felt/epoxy resin composites with different layer angle

• Carbon fiber felt based composites with different layer angle were prepared.
• Shielding effectiveness decreases with increase in layer angle.
• Ratio of absorbed power and reflected power can be regulated by layer angle.
• Composites with layer angle have potential for variable shielding applications.
• Shielding products with big layer angles need special attention for leaking wave.

Carbonyl iron powder-carbon fiber felt/epoxy resin composites with different layer angles were prepared to evaluate electromagnetic interference shielding properties in the X band. The average shielding effectiveness decreased from 53.9 dB to 8.6 dB with increase in the layer angle from 1.98° to 84.6°. The average power absorption coefficient increased first and then decreased, and had a maximum value at about 45°. The volume conductivity and the average dielectric constant decreased with increase in layer angle. It is found that the composites shield by absorption and reflection and the ratio depends on layer angle.