Improvements in Yttria Strength for Durable Windows

Processing options are explored by which the ultimate strength of yttria can be increased without adversely affecting any of yttria’s physical or optical properties, particularly its optical transparency in the band pass of interest. In this SBIR, the baseline approach will be a modification of the optical finishing process used to strengthen ALON™ optical ceramic. The processes developed at Surmet Corp. resulted in a greater than 2 times increase in the biaxial flexure strength of ALON™. There exists a multitude of fabrication processes and post-fabrication treatments which will be evaluated in order to ensure the best process possible for strengthening yttria. The specific process intended to be used for the fabrication of the yttria, like that used for the ALON™ strength enhancement effort, will be broken into its component parts and each evaluated for its potential use for strengthening yttria. Surmet believes that a significant portion of our success with strengthening ALON™ was due to the methodical approach used for process selection and evaluation.