Reaction Sintered Si <sub> 3 </ Sub> N <sub> 4 </ Sub> Matrix Composites

Reaction-sintered SiC/Si3N4 and reaction -sintered A1N /Si3N4 composite material were manufactured by quasi-static temperature-rising craft. The preparation craft, microstructure, pore ratio, surface hardness, bend strength and reaction theorem has been studied and analysed . The result showed the physical property of material molded by hydrostatic pressing is prior to that of material molded by uni-axial pressing. In the SiC/Si3N4 composite material, SiC partical dispersed uniformly in Si3N4 matrix, the pore ratio increased and the bend strength decreased with the increasing mass of SiC, the bend strength of material with 8% SiC is up to 141MPa. The melted silicon and β -Si3N4 could be seen in the A1N/SJ3N4 material because of the liquid phase appearing. Si3N4/AlN material which bend strength was 200Mpa could be prepared if prolong the heat preservation time near Al melting point.