Uniaxial dry pressing homogeneously dense powdered ceramic articles

The method of uniaxial dry compacting homogeneously dense powdered articles of complex shape excluding macroscopic defects has been developed. It is based on the effect of self-alignment of uniform density in a volume of green compact by different directed forces of die-wall friction. The equation defining density differential throughout the height of a green compact depending on its geometrical parameters and requirements of movement of die parts was proposed. The method allows preserving nanostructured state in the green compact because the shear component of plastic deformation dominates in the whole process of powder body compacting and so to achieve nanoscale grains at ceramics sintering. Also the method permits to avoid contamination and density gradients in the articles of complex shape. It was applied to produce nanostructured ceramic articles like impellers, plates with longitudinal holes. The die constructions for manufacturing various ceramic articles (complex and conic gear wheels, coils, bushes, segments of spheres and rings, etc.) were developed. This method is intended for production of structural and functional ceramic articles in electronics, telecommunications, aerospace, mechanical, chemical engineering, etc.