NDE OF INTERFACIAL BONDS BY MICRO-SCANNING GAMMA BACKSCATTERING

Award Information
Agency:
Department of Defense
Branch
Army
Amount:
$49,849.00
Award Year:
1990
Program:
SBIR
Phase:
Phase I
Contract:
n/a
Agency Tracking Number:
12994
Solicitation Year:
n/a
Solicitation Topic Code:
n/a
Solicitation Number:
n/a
Small Business Information
Spire Corp
Patriots Pk, Bedford, MA, 01730
Hubzone Owned:
N
Socially and Economically Disadvantaged:
N
Woman Owned:
N
Duns:
n/a
Principal Investigator:
Dr Charles C Blatchley
(617) 275-6000
Business Contact:
() -
Research Institution:
n/a
Abstract
ADHESIVELY BONDED STRUCTURAL MATERIALS REQUIRE NONDESTRUCTIVE METHODS OF INSPECTION AND EVALUATION (NDI/E) TO DETECT CRACKS, VOIDS, AND INCLUSIONS WHICH DIRECTLY AFFECT BOND STRENGTH. LACK OF RELIABLE NDI/E, PARTICULARLY DURING MANUFACTURE, WILL FORCE RELIANCE ON LARGE DESIGN MARGINS OF SAFETY AND EXPENSIVE DESTRUCTIVE TESTING. PHASE I WILL ADDRESS THESE NEEDS WITH GAMMA-RAY BACKSCATTER RADIOMETRY USING A COLLIMATED DETECTOR TO ACHIEVE NEAR MICROSCOPIC RESOLUTION. THIS IS SIMILAR TO BACKSCATTER TOMOGRAPHY (BOTH REQUIRE ACCESS TO A SINGLE SURFACE), BUT INSTEAD OF CREATING AN INTEGRATED IMAGE, INTERSECTING DETECTOR AND SOURCE VIEWS MEASURE DENSITY IN ONE PIXEL AT A TIME. FINER RESOLUTION IS ACHIEVED USING STACKS OF CONVERGING PLANAR VANES OR OTHER CONFIGURATIONS TO FOCUS THE VIEW TO A SMALL REGION. INSPECTION WOULD SCAN THIS REGION AT VARIOUS DEPTHS BELOW THE SURFACE OR COULD MAP A LARGER VOLUME AND THUS ENABLE DETAILED IMAGING. RECENT APPLICATIONS TO COMPOSITES SUGGET IT SHOULD BE POSIBLE TO ADJUST THE SENSITIVE VOLUME TO LESS THAN 1 MM(3), ENABLING DETECTION OF DEFECT SIZES ON THE ORDER OF A FEW MICROMETERS. PHASE I WILL DETERMINE FEASIBILITY OF SUCH MICROSCOPIC SCANNING IN REPRESENTATIVE COMPOSITE MATERIALS. PENDING THE OUTCOME OF THESE TESTS, A PROTOTYPE INSPECTION SYSTEM WILL BE DEVELOPED IN PHASE II AND CALIBRATED WITH APPROPRIATE DESTRUCTIVE TESTS.

* information listed above is at the time of submission.

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