Comparisons of grain size-density trajectory during spark plasma sintering and hot-pressing of zirconia

Spark plasma sintering (SPS) and hot-pressing (HP) of a granulated stabilized zirconia powder have investigated for a fixed macroscopic compaction pressure of 100 MPa and a fixed heating rate (25 degrees C/min HP, 50 degrees C/min for SPS). The relative density/grain size trajectories have been established for both methods. HP is shown to be similar to SPS for the manufacturing of polycrystalline TZ3Y materials with a final size well below the micrometer. Independently of the sintering technology employed, it is interesting to that three kinds of microstructures are obtained depending on the experimental parameters: materials (opened porosity, relative density between 61 and 90%) with a nanometer grain size (around 80 nm), dense materials (closed porosity, relative density between 90 and 98%) with a nanometer grain (around 75-80 nm), fully dense material with a submicron grain size (around 160 nm using SPS and 105 nm using HP). (C) 2008 Elsevier B.V. All rights