Abstract
The vibratory compacting of alumina powder has been investigated using a mechanical vibrator. In order to form small spherical granules, the almina powder is spray-dried with 6% waxes which induces a plasticity.
The results are as follows:
(1) Compacting pressures could be greatly reduced by applying vibration to both a die assembly and a loading weight.
(2) The maximum effect for the green density was observed in the first few seconds of vibration and after that the density of the vibratory compact increased gradually with vibration time.
(3) After 5 seconds, the vibratory compact reached a sufficient green strength to permit easy handling.
(4) The hardness of the sintered compact increased with the loading weight or the green density of the compact.
(5) In this technique the density variations of the green bodies was not improved, which gives an important problem in the conventional die compacting.
(6) When the vibratory compact was treated with isostatic pressing, the lower the green density, the harder the sintered compact was.
The application of the vibratory compacting to a production of powder pre-forms for the isostatic pressing is also discussed.
