Dynamic Powder Consolidation for Full Density and Nano Grain Preservation

Transparent polycrystalline ceramic nanomaterials benefit a host of military applications including as laser materials, transparent armor, and high strength windows. While current nanopowder processing techniques produce large quantities of quality ceramic nanopowders, they yield parts with sub-micron to micron grain sizes when manufactured by conventional press, sinter, and HIP methods or through hot pressing. Nevertheless, these parts still show promise for higher strength and optical performance compared to those produced from micron-sized starting powders. In order to reap the full property enhancement potential of nanopowders, the final sintered part must retain its nanograin structure (<100 nm). The proposed project will develop a dynamic, high-density (>70 %) green body compaction technique for ceramic nanopowders. Such compacts will enable sintering at lower temperature and for shorter times to reach full density, thereby preserving the desirable nanograin size in the final part. We anticipate such a process development will yield nanostructured bulk ceramics with mechanical and optical performance enhancements that lie well beyond those currently achievable at an affordable cost.