Carbon nanotube (CNT)-reinforced Y2O3/ZrB2 ceramics were fabricated via planetary ball milling and atmospheric-pressure plasma spraying for the first time. The phase composition, micromorphology, and electromagnetic (EM) wave absorption performance of the Y2O3/ZrB2/CNT hybrid was investigated from 8.2 to 12.4 GHz. Both the real and imaginary parts of the complex permittivity were enhanced as the ZrB2 and CNT content increased. The Y2O3/ZrB2/CNT hybrids corresponded to a ZrB2 content of 15 wt.%, and the CNT content was 2 wt.% and showed an exceptional EM wave absorption capability, with a minimum reflection loss of -25.7 dB at 1.9 mm thickness, and the effective absorption band was in a full X-band. These results indicate that an appropriate CNT or ZrB2 content can tune the complex permittivity and absorption performance of the Y2O3/ZrB2/CNT ceramics.
Keywords: Y2O3/ZrB2/CNT ceramics; dielectric property; microwave absorption; plasma spraying.