NDE OF INTERFACIAL BONDS BY MICRO-SCANNING GAMMA BACKSCATTERING

Award Information
Agency: Department of Defense
Branch: Army
Contract: N/A
Agency Tracking Number: 12994
Amount: $49,849.00
Phase: Phase I
Program: SBIR
Awards Year: 1990
Solitcitation Year: N/A
Solitcitation Topic Code: N/A
Solitcitation Number: N/A
Small Business Information
Spire Corp
Patriots Pk, Bedford, MA, 01730
Duns: N/A
Hubzone Owned: N
Woman Owned: N
Socially and Economically Disadvantaged: N
Principal Investigator
 Dr Charles C Blatchley
 (617) 275-6000
Business Contact
Phone: () -
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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