High temperature absorbing coatings with excellent performance combined Al2O3 and TiC material

A series of challenges are impeding the development of high temperature electromagnetic (EM) wave absorbing materials in x band. In this study, to deal with this problem, a coating, (1-x).wtAl₂O₃∼x.wtTiC, is designed and prepared using plasma spraying technology. Its permittivity increases with temperature and TiC content, which endows it with a good EM impedance at high temperature. The coating possesses excellent EM absorbing performance at 800 ℃. When the x value equals 0.2 and thickness 1.6 mm, the coating exhibits an EAB of 3.45 GHz at 800℃, and a reflection loss lower than -8 dB in whole x band. The XRD result shows that only two phases exist in the coating. The SEM images illustrate that TiC is unevenly dispersed in Al₂O₃, causing loss of conductivity and interface polarization. The finding not only broadens the application of TiC-based materials but also indicates the promising future of this material system.