The Control of Shape and Compaction Characteristics of Dry Ba-W-Ti-O Nanopowders by the Powerful Ultrasonic Action

Abstract

The compressibility of the dry BaTi4O9+BaWO4 (BWTO) and ZrO2-3% Y2O3 (TZ-3YS) nanopowders compacted by the ordinary uniaxial pressing, under powerful ultrasonic action (PUA) and by the novel collector method have been investigated. The coefficients of the logarithmic compaction equation in dimensionless form were determined from the experimental compaction diagrams. The BWTO nanopowder had low elastic component of these curves and low springback. The samples of parallelepiped shape (14 mm times 9 mm times 2 mm) were pressed. To decrease the shape distortion of sintered ceramics the green density difference along compaction axis was investigated. It was shown the possibility of green density difference reduction using PUA and collector method at optimal conditions. The uniform distributions of density in volume of the green compacts were achieved at compaction pressure of 640 MPa and power of ultrasonic generator of 2 kW at resonance frequency of 21 kHz.