Abstract Scope |
At the US Naval Research Lab we have been utilizing and developing processing routes in order to tailor unique microstructures in metals and ceramics. These techniques include 2 stage sintering, aerosol deposition, high pressure processing, microwave sintering, and electrically assisted sintering. The goal is to create fully dense bulk nanostructured ceramics. The impetus for this is the many theoretical and experimental studies showing tremendous enhancements in structural and functional properties of nanostructured materials such as improvements in magnetic exchange coupling, thermoelectric energy conversion, and mechanical response. However, these improvements are generally only expected when porosity is negligible and the microstructural length scales are well below 50 nm, which is a technological challenge, especially in nanocrystalline ceramics processing. Two techniques that will be highlighted are NRL’s Environmentally Controlled Pressure Assisted Sintering (EC-PAS) and Aerosol Deposition. Using these approaches, fully-dense nanocrystalline ceramics and thick films with grain sizes <10nm have been synthesized.. |