Densification behaviour analysis of ZrO2 nanopowders for dental applications compacted by magnetic pulsed compaction

Sintered bulks of commercial ZrO2 nanopowders were produced by combined application of magnetic pulsed compaction (MPC) and subsequent two-step sintering, and finally, their density, hardness, shrinkage and formability were analyzed. The formability tests were conducted by a CAD/CAM system. Nearly fully dense (∼98%) commercial ZrO2 bulks were successfully obtained. With increasing MPC pressure, there was a decrease in the grain size of zirconia block. The ratio of PVA did not have a remarkable effect on the grain size. The optimum compaction pressure during MPC was 1 GPa and mixing conditions included using 1.0 wt. % PVA. The optimum processing condition included MPC process, followed by two-step sintering (first at 1000 and then at 1450 °C). The bulk under these conditions was found to have good formability, ∼97% density, reasonable hardness (1150 Hv) and ∼19% shrinkage.