Differential porosity ceramic parts - made by successive quasi-isostatic cold pressing followed by single sintering

摘要

Ceramic parts comprising two differential porosity layers are prepd. with the aid of additives by the cold pre-pressing of the first layer in a quasi isostatic mould following which a second layer is similarly formed. The composite is then subjected to elevated compacting pressure and is then placed in a furnace and sintered. Varying amts. of ammonium bicarbonate additives are used to act as porosity controllers. This is pref. removed in vacuum at 150-200 degrees C prior to sintering. The process is used for electronic components, solid fuel cell electrolytes and ZrO2 and Al2O3 high temp. acculumators.