Pressure consolidation of amorphous ZrO2–Al2O3 by plastic deformation of powder particles

Amorphous $ZrO_2–Al_2O_3$ powders undergo densification at low temperatures $(<650^o\hspace {2mm}C)$ and moderate uniaxial pressures (~750 MPa). It is established that large pressure dependent densification and little time dependent densification occur. Viscous sintering is not the dominant densification mechanism. Study of the particle size effect in densification of amorphous $ZrO_2-40\%\hspace{2mm} Al_2O_3$, and comparison with hot pressing of borosilicate glass powder at 500 and 550°C and cold compaction of silver powder, clearly indicate the possibility of compaction of amorphous $ZrO_2-Al_2O_3$ by plastic deformation. Good agreement was seen between a model for the compaction of ductile metal powders and the observed hot pressing behaviour.