Aqueous Gel‐Forming of Silicon Nitride Using Carrageenans

摘要: Much effort has been devoted recently to the development of near-net-shaping processes in water. Agarose demonstrated be a suitable gelling agent for aqueous forming. However, its high cost and difficulties controlling rheological properties have restricted large-scale applications. In this work novel binder, namely carrageenan, is proposed as low-cost high-gel-strength additive gel-forming ceramic powders. The capability obtain silicon nitride parts by carrageenan gelation described. Aqueous slips are prepared at pH >11 solids content 70 wt% using tetramethylammonium hydroxide dispersant. Dissolution studied continuous measurements viscosity with temperature solutions different values. final injection mixing <60°C previously heated suspension solution rheologically characterized also. After blend injected into cooled nonporous molds, occurs few seconds samples can dried air 24–48 h. Green densities 52% theoretical obtained.