Low Cost Production of High Purity and Phase Pure Ultrafine Powders of MgAl2O4 Spinel

In Phase I, we demonstrated that high purity nanoparticles of spinel MgAl2O4 can be synthesized using a novel chemical synthesis process that was recently invented by us. To the best of our knowledge, this is the first time that nanopowders of MgAl2O4 haveever been synthesized. Sinterable spinel MgAl2O4 nanopowders are needed to fabricate fine grained (micron to sub-micron range) and transparent ceramic objects for use primarily in missile and armor applications. Spinel materials possess certain uniqueoptical properties that are superior to those of the more expensive sapphire, which is currently used. In addition, fine-grained materials have the potential to display excellent mechanical properties. In the proposed Phase II program, the synthesisprocess demonstrated in Phase I will be developed so that we can be a supplier of high quality spinel MgAl2O4 nanopowders for military and commercial applications, with an emphasis on reproducibility. Microstructural evolution during sintering will bestudied, and feedback will be used to optimize the powder properties. Spinel MgAl2O4 powders will be provided to our collaborator, a commercial manufacturer of transparent ceramics, and 4 inch diameter discs will be fabricated and characterized for opticaland mechanical properties. Nanopowders will also be delivered to the Army as required.Transparent ceramics offer a number of opportunities in both military and civilian applications, including infrared windows in missiles and optical systems. The totalmarket for such components is in the several tens of millions of dollars. The nanopowder synthesis process being developed in this program is also suitable for producing high quality doped and multi-component oxides for a variety of functionalapplications, including rechargeable Li-ion batteries, photonic devices and chemical gas sensors. The total estimated market for these applications is in the several hundreds of millions of dollars.