CONTROLLED MICROSTRUCTURAL DEVELOPMENT OF SI(3)N(4) TO ENHANCE FRACTURE TOUGHNESS

Award Information
Agency:
Department of Defense
Branch:
Army
Amount:
$479,707.00
Award Year:
1993
Program:
SBIR
Phase:
Phase II
Contract:
N/A
Agency Tracking Number:
15900
Solicitation Year:
N/A
Solicitation Topic Code:
N/A
Solicitation Number:
N/A
Small Business Information
Materials & Electrochemical Rs
7960 S Kolb Rd, Tucson, AZ, 85706
Hubzone Owned:
N
Socially and Economically Disadvantaged:
N
Woman Owned:
N
Duns:
N/A
Principal Investigator
 Lori A Leaskey
 Principal Investigator
 (602) 574-1980
Business Contact
Phone: () -
Research Institution
N/A
Abstract
SILICON NITRIDE IS AN ADVANCED CERAMIC MATERIAL WITH EXCEPTIONAL PROPERTIES. HOWEVER, A SEVERE PROPERTY LIMITATION IS OBSERVED IN THE LOW FRACTURE TOUGHNESS OF SI(3)N(4). THE POTENTIAL FOR UTILIZATION OF SI(3)N(4) CERAMICS IN MANY APPLICATIONS WOULD BE SIGNIFICANTLY IMPROVED IF ITS FRACTURE TOUGHNESS COULD BE INCREASED WITHOUT SACRIFICING HIGH TEMPERATURE STRENGTH. IT IS PROPOSED THAT THE ABOVE CAN BE ACCOMPLISHED THROUGH MANIPULATION OF THE MICROSTRUCTURE OF SI(3)N(4) TO PRODUCE A MIXTURE OF ACICULAR AND EQUIAXED GRAINS. THIS CAN BE ACHIEVED BY NANOCOATING INDIVIDUAL SI(3)N(4) PARTICLES WITH RARE EARTH OXIDES (Y(2)O(3), ND(2)O(3), AL(2)O(3) OR SOME COMBINATION). CONTROL OF THE AMOUNT AND TYPE OF COATING, AND RATIO OF COATED TO UNCOATED PARTICLES WILL ALLOW CONTROL OF THE RESULTING SI(3)N(4) MICROSTRUCTURE TO EFFECT THE DESIRABLE PROPERTIES. ALSO, THE UNIFORM DISTRIBUTION OF THE COATING IN A CONTROLLED AMOUNT TO LIMIT GLASSY PHASE FORMATION WILL RESULT IN A HOMOGENEOUS COMPOSITE WITH DECREASED PORTABILITY FOR HIGH TEMPERATURE DEGRADATION.

* information listed above is at the time of submission.

Agency Micro-sites

US Flag An Official Website of the United States Government