Formation regularities of structures of AlN-SiC-based ceramic materials

Composite materials based on AlN-SiC have been produced by the pressureless sintering. It has been established that in the formation of the AlN-SiC-Y3Al5O12 structure the yttrium-aluminum garnet locates along the boundaries of SiC and AlN grains, thus preventing the mutual dissolution of AlN-SiC. It has been found that the increase of the SiC amount from 20 to 50 wt % results in changes of the a and c parameters of the crystal lattice from 0.49821 to 0.49837 nm and from 0.5046 to 0.498 nm, respectively, and in increase of the composite absorbing ability from 8.8 to 31.4 dB/cm (at frequencies of 9.5–10.5 GHz).