A novel approach to pressureless sintering based on the combination of rapid‐rate sintering, rate‐controlled sintering, and two‐step sintering under a controlled atmosphere is proposed. This combined sintering method facilitates control of grain and pore morphology. The application of this sintering approach for pure nanocrystalline barium titanate powder enables the suppression of grain growth during the intermediate and final stages of sintering and the production of fully dense ceramics with 108 nm grain size. The grain growth factor is 3.5, which is three and 17 times smaller than rate‐controlled and conventional sintering, respectively.

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Thermally-stable recovered energy density and significant electrocaloric temperature change over a broad temperature span in BCZT ceramic elaborated by low-temperature hydrothermal processing.

This review is dedicated to the problems of nanostructured ceramics consolidation.Laboratory practice in recent years has displayed several potentially important technologies for consolidation of ceramic nanopowders, such as spark plasma sintering, high pressure sintering and rate controlled sintering. The grain growth factor in these processes was found to be less than 10. These advanced technologies have to be adapted to consolidation of nanopowders and require nanopowders specifically designed for consolidation purposes. When adapted to nanopowders, these techniques must be accomplished in rapid rate mode to eliminate residual porosity and retain nanosize grains. Practical verification, however, has exposed problems such as large residual porosity, stable pores in triple junctions, defective grain boundaries and intensive grain growth. All these problems can be avoided when the temperature-pressure-time schedule of sintering is optimised with respect to minimal grain growth.

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