Ultrasonic vibration press of metal and ceramic powders using complex vibration and vacuum condition

Ultrasonic vibration press of metal and ceramic powders using complex vibration punches under vacuum conditions is studied. Upper and lower 20 kHz longitudinal vibration compacting punches vibrating at anti-phase or in-phase mode and a vacuum compacting die are used. Using vibration punches or a vacuum die, compact density is increased over that obtained using only static pressure. Using only a vacuum die, the increment of compact density is rather small. Using an upper and a lower vibration punch and a vacuum die simultaneously yields a larger compact density. The hardness of piezoceramics (PZT) pressed by this method was about double that without vibration and vacuum condition under a static compacting pressure of 147 MPa. This method may be also effective for other ceramics or plastic powder