Formation Regularities of Structures of AlN–Si- 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 aand 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).