Performance of Mullite Matrix Microwave Absorber Coatings Fabricated by Plasma Spraying Technology
等离子喷涂纳米莫来石基复合吸波涂层性能研究

The clusters of mullite matrix (steatite, carbon) composite absorber powders were produced by using spraying spheroid granulator, and the composite powders were used to fabricate composite microwave absorber coatings by plasma spraying technique. The results show that during the plasma spraying, the carbon is oxidized, and the steatite is decomposed to enstatite and quartz for the high temperature plasma gas. The experiments show that the mean adhesive strength of coatings decreases with the coating thickness increasing, which reaches 2MPa with thickness of 0.8mm. The crack extracted the coatings rupture surface with wavelet maximum module exists in the glass phase interface. For these coatings, with the coatings thickness increasing, the reflectivity coefficient transforms to low frequency; while with the complex permittivity of enstatite increasing, it decreases and transforms to high frequency. The reflectivity coefficients of the coatings with thickness of 0.8mm are all below -5dB in the frequency range from 15GHz to 18GHz.