Project MECERDIS has developed several novel methodologies for dislocation engineering in ceramics, with a particular focus on room-temperature deformation at meso/macroscale, contrasting the conventional picture that this is impossible for ceramics due to their being hard and brittle. For instance, in Project MECERDIS, we have proposed the original idea of “mechanically seeded dislocations” to overcome the dislocation nucleation (which requires extremely high shear stress and most ceramics would have already fractured before such a high shear stress can be achieved) to facilitate the dislocation motion and multiplication, hence promoting the dislocation plasticity even at room temperature in various ceramic materials. This constitutes a fundamental component for Project MECERDIS to build up this so-called "Deformation toolbox" to mechanically engineer dislocations at room temperature across the length scales (from nanoscale up to bulk, i.e. millimeter or larger samples), with a tunable dislocaiton density over 4-5 orders of magnitude from e.g. 10^10/m^2 to 10^15/m^2, in a fast and cost-effective manner, holding great potential for applications.
Based on the "Deformation toolbox", the "Materials toolbox" is being extended as well. So far, the most "well-known" plastically deformation ceramics at macroscale at room temperature have been known to be e.g. rock salts, MgO, SrTiO3, with just a very limited total number of them, ever since the first studies dating back to the 1920s. Project MECERDIS has been able to report KTaO3 as the 3rd perovskite oxide to exhibit room temperature bulk plasticity in 2024. This discovery has already generated a huge impact in the ceramic community, considering the 1st one being SrTiO3 was reported in 2001, and the 2nd one being KNbO3 reported in 2016. This breakthrough indeed opens many new doors for Project MECERDIS to extend the materials much more beyond just these 3 materials, using the “alloying” concept borrowed from the metal community, and the outcome may be considered revolutionary for the ceramic community. This will lay a solid ground for dislocation-tuned functional ceramics at room temperature, without the need for high-temperature treatment to potentially save a tremendous amount of energy once scaled up for mass production/processing. This is clear evidence for fundamental research that may lead to new breakthroughs.
Another major achievement is the successful crack suppression framework developed in project MECERDIS, with extension from single crystal to bicrystal materials and polycrystalline samples (first demonstrated on SrTiO3 and MgO in Project MECERDIS), a major step ahead for further extending the materials toolbox. These findings have already been proven helpful using this fundamental defect (dislocation as line defect) for many other potential applications, such as boosting the functional properties, increase the hydrogen production rate, and enhancing the mechanical properties for next-generation functional oxides for the energy transition.
