Thermal-Shock-Resistant Sensor Windows and Domes for High-Speed Flight Made of Low-Expansion Ceramics

Period of Performance: 12/31/2009 - 07/01/2011

$500K

Phase 2 STTR

Recipient Firm

Materials & Systems Research, Inc.
5395 West 700 South Array
Salt Lake City, UT 84104
Principal Investigator
Firm POC

Research Institution

University of Utah
75 S 2000 E
Salt Lake City, UT 84112
Institution POC

Abstract

This Small Business Technology Transfer Research (STTR) Phase II proposal from Materials and Systems Research, Inc. (MSRI) and University of Utah (research institution) seeks to fabricate single-phase, polycrystalline tungstate ceramics with densities greater than 99.95% and a mean grain size of less than 1 um. These ceramics have been chosen because of their low thermal expansion and low elastic modulus that render them highly thermal-shock resistant and, therefore, suitable for IR windows and domes in high-speed flight. The optical transmittance of these polycrystalline ceramics is expected to be comparable to that of sapphire in the midwave (3-5 um) and long wave (8-14 um) infrared ranges. The high density and small grain size will be achieved by a fabrication route that will combine the following steps: preparation of a stable suspension of submicron powders, forming a green compact by pressure filtration, and a two-stage densification by pressureless sintering followed by hot-isostatic pressing. The proposed fabrication route has two distinct advantages over conventional powder processing methods: (a) it eliminates microstructural inhomogenities that limit strength, durability and optical transmittance in conventional powder processing, (b) it eliminates a number of steps involved in conventional processing and leads to a lower cost. Research in Phase II will fabricate disks 50 mm in diameter and 2-3 mm in thickness. Material characterization will be done by University of Utah under a subcontract.