This research consists of a three year study of crack healing and pore morphology evolution using engineered flaws in controlled-misorientation doped and undoped sapphire bicrystals. The flaws are created by photolithographic techniques which allow, for the first time, detailed and independent analyses of the effects of grain boundary misorientation (structure) and chemistry on high temperature crack healing and pore morphology evolution processes (which occur in sintering and diffusion bonding of ceramics and multilayer laminates). Detailed characterization of these processes is being done using optical microscopy, scanning electron microscopy, and scanning transmission electron microscopy with microchemical analysis.
