9505859 Raj The objective of the proposed work is to develop predictive methods for the design of directional microstructures for the purpose of obtaining very high resistance to deformation and fracture at very high temperatures. The approach is based on coupling the local atomistic mechanisms of time dependent nucleation and growth of cavities at interfaces, and the long range relaxation of the stress concentrations accompanying cavitation, with the stochastic distribution of nucleation sites in the specimen. The proposed work is both experimental and theoretical. The results will be applied specifically to high temperature silicon nitride ceramic. %%% The proposal is aimed to develop predictive methods for the design of directional microstructures for the purpose of obtaining very high resistance to deformation and fracture at very high temperatures.
