October 30, 2006 – nGimat Co. has been awarded a one year, $390,000 Phase II Small Business Innovative Research (SBIR) project with a second optional year consisting of an additional $360,000 to develop yttrium aluminum oxide nanopowder that can be processed into transparent, small grained polycrystalline, laser host materials. The research project is funded by the Office of the Secretary of Defense and is monitored by the Army Research Laboratory in Adelphi, MD.
Successful completion of Phase II objectives will position nGimat to sell nanopowder for production of military and commercial High Energy Laser (HEL) systems. Solid-state lasers are used in a variety of industrial applications including materials processing, healthcare, basic research, instrumentation, and microelectronics. According to Business Communications Company, Nd:YAG materials account for ~ 65 to 90% of sales in various sectors of the $1.0 billion solid state laser market.
In the previous Phase I effort, nGimat succeeded in producing high purity, crystalline nanopowders that were pressed and sintered into polycrystalline Nd doped YAG pellets. This Phase II program will enable further development and manufacturing scale up to produce commercial quantities of ultrapure unagglomerated yttrium aluminum oxide nanopowder with a particle size less than 100 nm in diameter.
“Sintering nGimats nanocrystals into transparent polycrystalline solids with submicron grain size would alleviate many of the manufacturing limitations associated with growing YAG single crystals,” said Andrew Hunt, CEO of nGimat. “YAG single crystals require expensive machining and are limited in the size that may be produced. Nanopowder processing enables net shaped part formation of almost any size without expensive ceramic machining. nGimat will utilize its high volume, cost-effective NanoSpraySM Combustion process for production of nanopowders that may then be processed using traditional ceramic processing methods into polycrystalline laser host materials.”
The key to using nanomaterials is that they enable formation of fully dense polycrystalline ceramics while utilizing lower processing temperatures. The resulting bulk material exhibits very high light transmission similar to that of more expensive single crystalline lasers. Traditionally processed polycrystalline ceramics exhibit increased light scattering (poor transmission) resulting in reduced lasing performance. Light transmission is of high importance in laser host materials, as is the light emitting dopant concentration. Currently, single crystalline neodymium-doped yttrium-aluminum-garnet (Nd:YAG) is the state of the art in solid state lasers. However, YAG single crystals have several disadvantages including high manufacturing cost, limited size and shape, and low concentration of the light emitting element (neodymium, Nd). Nd is limited to 1% concentration via melt processing, but nanomaterials enable higher percentages to be incorporated into the YAG lattice which improves laser efficiency and intensity. Thus using very small powders benefits the end product in two ways over larger grained powders.