For over 25,000 years, human-kind has been using a manufacturing process known as sintering that uses both high temperatures and long processing times. It is believed that we are no longer confined to these high energy, inefficient traditional strategies. Through the use of the transient liquid phase, it has been found that ceramic materials can be sintered at unprecedented low temperatures. Through accelerated stimulus with ultrasound, it is hypothesized that even lower temperatures in greater efficiencies in the sintering process can be gained for a broad variety of inorganic materials, including the possible use in refractory materials, such as bricks. With such energy reductions in the process, it is anticipated that future techniques would be more efficient and lower cost.
TECHNICAL DETAILS: The kinetics of sintering in terms of densification and grain growth are considered and quantified in simple binary materials under cold (at or under 300°C) sintering conditions. Detailed structural studies are being correlated with the various stages of sintering. Densification kinetics are being determined with a dilatometer in a modified mechanical tester. Transmission electron microscopy and impedance spectroscopy are being used to consider defect microstructure, stoichiometry, and defect chemistry monitoring differences in the cold sintering relative to process parameters. This base line data on model binary oxide systems provides critical insights into the nature of the cold sintering mechanisms. A complementary effort builds on those investigations and addresses the question on if and how ultrasonic radiation can be utilized to enhance the kinetics of cold sintering. There is literature pointing to ultrasonic radiation and sonochemistry that can improve particle compaction, dissolution, and precipitation, naturally leading to the conjecture that many mechanisms and stages of the cold sintering will be positively impacted.
