Infrared Transparent Nanocrystalline Alumina

Award Information
Agency: Department of Defense
Branch: Navy
Contract: N41756-05-M-1392
Agency Tracking Number: N042-173-0262
Amount: $69,999.00
Phase: Phase I
Program: SBIR
Awards Year: 2005
Solitcitation Year: 2004
Solitcitation Topic Code: N04-173
Solitcitation Number: 2004.2
Small Business Information
SIENNA TECHNOLOGIES, INC.
19501 144th Avenue NE, Suite F-500, Woodinville, WA, 98072
Duns: N/A
Hubzone Owned: N
Woman Owned: N
Socially and Economically Disadvantaged: N
Principal Investigator
 Ender Savrun
 President
 (425) 485-7272
 ender.savrun@siennatech.com
Business Contact
 Canan Savrun
Title: Vice President
Phone: (425) 485-7272
Email: canan.savrun@siennatech.com
Research Institution
N/A
Abstract
This SBIR program will produce nanocrystalline, dense a-Al2O3 samples with high IR transparency by utilizing novel processing techniques starting with properly seeded transition alumina powders. Alpha alumina does not exist naturally in the environment and is synthesized by a number of various processes. Many of these processes generate wide particle size distributions and are generally agglomerated. If a homogeneous microstructure is not achieved, higher sintering temperatures are required to eliminate the porosity, compromising the fine grain size of the final product. The addition of seed particles, which are isostructural with a-Al2O3, provide low energy sites for heterogeneous nucleation to occur and reduce the energy barrier required for nucleation. Uniform microstructures of 100 nm or less a-Al2O3 can be achieved after the phase transformation with proper seeding. Gel-casting will be used to produce complex ogive shapes with green densities > 55%, which will be subsequently sintered to full density at lower temperatures than die pressed samples. A rapid microwave sintering technique will demonstrate that fine nanostructures can be achieved by increasing the densification kinetics and reducing the time at which grain growth can occur.

* information listed above is at the time of submission.

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