The High Speed Centrifugal Compaction of Submicron Ceramic Powder in Fusible Alloy Die

The technology required to make fine ceramic products with complex shapes involves forming uniform and high-density compacts with fine powders of less than 1μm. To achieve this, a high speed centrifugal compaction process has been developed by the authors that applies a centrifugal force of 10 k-20 kG to a slip of ceramic powder in a metal die. This process offers a faster compaction rate than that of previous techniques but with no contamination. The present study concerns an extraction method for this process. An alumina slip is loaded in a monocoque die manufactured using a fusible alloy, that places a high yield ratio and no restrictions on product shape. After centrifugal compaction, the die is melted and the compact extracted. Since the compact would be contaminated when the compact and metal become wet after the die is melted, a method in which a thin expandable film separates the die and the compact is contrived. This technique makes it possible to produce a pure compact with sintering at a low temperature of 1250°C in the atmosphere.