Abstract
The alumina powder added with sodium stearate as a lubricant was compressed by Cyclic-CIP and the change in relative density of the alumina compacts was investigated, Sedimentation experiments indicated that the addition of sodium stearate (≧2wt%) resulted in uniform adsorption of sodium stearate on surface of the alumina powder. By compressing the alumina powder added with sodium stearate repeatedly (Cyclic-CIP), the density of the alumina compacts reached to 63% or larger when the applied pressure was as low as 100MPa. This density coincided with the density of the alumina compacts which was compressed by ordinary CIP at 500MPa. By adding sodium stearate to the alumina powder a high density compact was obtained for a few cycles. It meant that the addition of lubricant to the powder was effective for Cyclic CIP as well as ordinary CIP. From pore size distributions of the compacts, it was suggested that the rearrangement of primary particles was promoted by compressing powder repeatedly.
