Preparation and microwave attenuation performance of AlN-SiC composites

AlN-SiC composites were prepared by hot-pressing with AlN and β-SiC as the starting materials at the temperatures ranging from 1900 to 2000°C for 1 h in a nitrogen atmosphere. The effect of the microwave attenuator SiC content and the formation of the solid solution on the microwave attenuation performance of the AlN-SiC composites was studied by XRD, high resolution transmission electron microscopy and network analyzer. The results show that the frequency band attenuation performance is changed with the content of the attenuator SiC. There are narrow frequency band attenuation performances for AlN-SiC composites with lower mass fraction of SiC (<40%), while there are wide frequency band attenuation performances for AlN-SiC composites with the SiC content of 40%-60% (in mass). The formation of partial AlN-SiC solid solution is helpful to improve the wide frequency band attenuation performance of AlN-SiC composites.