Preparation of silicon carbide with high properties

in order to prepare silicon carbide with high properties, three kinds of Si C powders A, B, and C with different composition and two kinds of additives . which were Y2O3-Al2O3 system and Y2O3-La2O3 system, were used in this exp eriment. The properties of hot-pressed SiC ceramics were measured. With the same additives, different SiC powder resulted in different properties. On the other hand, with the same SiC powder, increasing the amount of the addi tive Y2O3-Al2O3 improved properties of SiC ceramics at room temperature, an d increasing the amount of the additive Y2O3-La2O3 improved property SiC ce ramics at elevated temperature. In addition, the microstructure of SiC cera mics was studied by scanning electron microscopy.