Energy Coupled to Matter Research for Field-Enhanced Processing of Ceramic Materials

Energy Coupled to Matter (ECM) research at the U.S. Army Research Laboratory (ARL) is focused on the study of material interactions with external fields to produce outcomes that are unattainable through conventional means, expanding materials-by-design and processing science capabilities beyond the current state-of-the-art. Research has been conducted to utilize these innovative technologies and material solutions for exploring structure-property relationships of ceramic materials based on their interactions with applied fields. The application of magnetic, electric, microwave, and other types of external fields during heat treatment often has a profound influence, altering the free energy of the system and enabling densification of materials at lower temperatures and shorter times compared to standard sintering processes. The ability to rapidly densify materials under less extreme processing conditions can allow for preservation of the nanoscale, providing the opportunity to improve mechanical properties that are vital to Army protection applications, including strength, hardness, and fracture toughness. In addition, techniques for manipulating materials to make them more responsive to specific fields have been investigated to amplify these effects. Fabricating ceramic materials containing rare earth/transition metal dopants or ferromagnetic additives has helped to increase the response to applied magnetic fields, influencing phase formation and enhancing susceptibility, conductivity, and other key magnetic properties. Similar parallels have been explored for the integration of electrically conductive phases that generate pathways to enhance electric field processing, and susceptor materials that react to microwaves and induce localized heating. Strategies in experimental design, computational modeling, and in-situ characterization have been employed to develop unique ECM processes for field-enhanced processing of unique components. These revelations have led to increased interest in the influence of fields over material phases and properties.