Study of the densification and grain growth mechanisms occurring during spark plasma sintering of different submicronic yttria-stabilized zirconia powders
Abstract
Densification and grain growth mechanisms of Yttria-Stabilized Zirconia sintered by Spark Plasma Sintering are
investigated. Sintering trajectories of four commercial submicronic powders with different average particle sizes
and yttria amounts have been established and sintering regimes determined. Densification mechanisms are
determined in the regime where densification is occurring without grain growth using a model derived from hotpressing.
Grain growth mechanisms are determined using the conventional power law in the regime where ceramics
are fully densified. Densification occurs by grain boundary sliding accommodated by an in-series interface-
reaction/lattice diffusion of cations or by an overlapping of surface diffusion and grain boundary sliding
mechanisms for tetragonal stabilized zirconia and by dislocation climbing for fully stabilized zirconia. A normal
grain growth occurs for each ceramic, all composed of a single phase, contrary to the two-phased ceramics
obtained in literature where grain growth occurs by segregation at grain boundaries.
Origin : Files produced by the author(s)