Sintering Ceramics at Room Temperature using Phase-Changing Additives

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Up to 90% of the energy used over the lifetime of a ceramic component is consumed during manufacturing. The very high temperatures used are by far the biggest barrier to the wider use of ceramic materials, despite their suitability for use in a wide range of applications including solid-state batteries and other devices. In this project we will attempt to eliminate the need for heating to densify ceramic materials. We will start with pellets pressed from highly pure ceramic powders to which we will add very carefully controlled amounts of "phase-changing additive" substances which convert to metals at relatively low temperatures. This will provide us with a way to input energy by connecting the material to a power supply which will preferentially heat the surfaces of the particles where these substances are placed. We hypothesize that this will lead to intense heating in this region locally, enabling sintering to occur without needing to raise the temperature of the entire sample. This paradigm-shifting idea would radically reduce energy consumption in the ceramics industry and enable co-processing of ceramics with other materials which would usually degrade at the high temperatures of conventional ceramic processing methods. This work, if successful, will enable better manufacturing routes for important technological applications including solid-state batteries and ceramic-based metalized metamaterials for use in imaging and communication. In this project we propose several methods to investigate whether our hypothesis is correct and whether the effects we propose can be sufficiently controlled to lead to extensive densification. We will also investigate how universal the effects are by substituting materials with different ionic, electrical, and thermal conductivities. The project will also involve extensive work to characterise the samples produced using a wide range of imaging, X-ray spectroscopy, and bulk property measurement methods.