PURPOSE: To improve surface properties by putting a porous material of SiC in a crucible placed on a pedestal having a heat capacity larger than that of a SiC-Si composite material, then adding small pieces of Si, melting, impregnating Si into the porous material of SiC and then cooling.
CONSTITUTION: A porous material 1 of SiC such as a cylindrical material molded from β-SiC powder is vertically stood on a graphite crucible 3 on a pedestal 4 such as quartz having a heat capacity larger than that of a SiC-Si composite material, small pieces 2 of Si in an amount to give about 1.2 the whole volume of pores are put in the periphery of the porous material of SiC. The small pieces 2 of Si are heated under pressure at 1,400-1,600°C, melted and impregnated into the porous material 1 of SiC. Then when the material impregnated with the molten Si is cooled, coagulation is advanced from the upper part of the porous material 1 toward the lower part. Since Si corresponding to volume expansion is returned to the crucible, a SiC-Si composite material 1 free from oozing of Si on the surface is obtained. In the case of putting the small pieces of Si in an amount to give ≥1.5 the whole volume of pores in the crucible 3 and impregnating into the porous material 1, a SiC-Si composite material free from oozing of Si is obtained without using the pedestal 4.
MINAGAWA KAZUHIRO
ARAHORI TADAHISA
