摘要 |
PURPOSE:To prevent the agglomeration of SiC powder and to improve the homogeneity of the ceramic by specifying the pH of a slurry in the mixing and dispersing in the production wherein SiC as the essential component and a B-C based sintering assistant are mixed and dispersed. CONSTITUTION:An SiC ceramic contg. SiC as the essential component, >=1 kinds among B, B4C, Al, Al2O3, etc., as the sintering assistant, and >=1 kind among carbon black, phenolic resin, and tannin is produced. In the production, the pH of the slurry obtained by mixing the sintering assistant, SiC powder, and water varies between 4 and 7 in accordance with the kind and amt. of the sintering assistant added. Under such conditions, the SiC powder agglomerates even when a water-soluble sintering assistant is used to uniformly mixing and dispersing the materials. Accordingly, the pH of the slurry is controlled to 8-12, and then forming and calcination are carried out. By this method, a dense product consisting of the particles having a small diameter and having high-temp. strength and corrosion resistance is obtained. |