Multi-Scale Study of Nanoparticle Sintering

Virginia Polytechnic Institute And State University, Blacksburg VA

Investigators

Abstract

This grant provides funding for a nanoparticle sintering study across multi-scales through quantifying three-dimensional (3D) structural evolution of different nanoparticle packings and connecting the microstructural characteristics with macroscopic shrinkage. The primary issues to be addressed are particle agglomeration, excessive grain growth, complex nano-/micro-structural evolution, and non-uniform shrinkage. Sintering is a high temperature process whereby particles, in this case nanoparticles (with diameters less than 100 micrometers), are consolidated into solid form. The process involves multi-scale events that range from atomic diffusion to macroscopic shrinkage and creates stable nanostructures for long term use. Experiments will be carried out to create homogeneous and agglomerated titanium dioxide and zirconium dioxide nanoparticle packing structures across all scales. The resulting nanostructure will be quantitatively described and correlated with grain growth and macroscopic shrinkage through nanostructural electron tomography and focused ion beam 3D rendering. If successful, the results of this research will provide understanding to the key issues in nanoparticle sintering. These include the effects of different nanoparticle packings, excessive grain growth, complex nano-/micro-structural evolution, and non-uniform shrinkage. The team will develop theories that link nano-/micro-structural evolution and macroscopic densification throughout the entire sintering process. The integrated understanding across multi-scales will provide comprehensive sintering knowledge and enable the field to challenge the heretofore-accepted sintering theories and perspectives. With proper adjustment, the methodology and breakthrough can also be applied to conventional micron-sized particle sintering which has numerous applications. New theory-guided sintering processes resulting from this program will also allow for more energy efficient sintering practices. The research methodology has wide-ranging significance in multi-scale device integration while improving process reliability and manufacturability.