Abstract
Carbon black (CB)/cordierite composite coatings with different CB contents were fabricated by a multi-function micro-plasma spraying system developed by the Second Artillery Engineering College. Scanning electron microscopy was employed to investigate the microstructure of the spray-dried powders and as-sprayed coatings. The complex permittivities of the coatings and powders with different CB contents were investigated at the frequency of 8.2-12.4 GHz. The results show that both real and imaginary part of the permittivity increase with increasing CB content, which can be ascribed to the increase of the number of micro-capacitors and the polarization centers. Reflection loss of the as-sprayed coatings with different CB contents and thicknesses was calculated according to the transmission line theory. The coating with 4.54% CB content and 3.0 mm thickness shows optical microwave absorption with a minimum reflection loss of −23.90 dB at 10.13 GHz and reflection loss less than −9 dB over the whole investigated frequency.
Original language | English |
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Pages (from-to) | 826-835 |
Number of pages | 10 |
Journal | Journal of Thermal Spray Technology |
Volume | 24 |
Issue number | 5 |
DOIs | |
State | Published - 28 Jun 2015 |
Keywords
- carbon black/cordierite coating
- dielectric property
- plasma spraying
- reflection loss