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Multi-Modal Sensing of Sensitization and Stress Corrosion Cracking Susceptibility in AA5xxx Alloys

Award Information
Agency: Department of Defense
Branch: Navy
Contract: N68335-20-C-0322
Agency Tracking Number: N18A-010-0183
Amount: $1,000,000.00
Phase: Phase II
Program: STTR
Solicitation Topic Code: N18A-T010
Solicitation Number: 18.A
Solicitation Year: 2018
Award Year: 2020
Award Start Date (Proposal Award Date): 2020-02-28
Award End Date (Contract End Date): 2022-03-03
Small Business Information
301 1st Street SW Suite 200
Roanoke, VA 24011
United States
DUNS: 627132913
HUBZone Owned: No
Woman Owned: No
Socially and Economically Disadvantaged: No
Principal Investigator
 Matthew Webster
 Principal Investigator
 (434) 220-2514
Business Contact
 Michael Pruzan
Phone: (540) 769-8430
Research Institution
 The Rector and Visitors of the University of Virginia
 Ruthanne Porreca Ruthanne Porreca
P.O. Box 400195
Charlottesville, VA 22904
United States

 (434) 297-7402
 Nonprofit College or University

In order to travel faster, travel longer, and carry larger payloads, new Navy ships are being designed with light weight alloys and composite materials. High magnesium AA5xxx series alloys provide a high strength to weight ratio and excellent corrosion resistance, but suffer from sensitization as anodic ß precipitates (Al¬3Mg2) are form along grain boundaries due to a combination of elevated temperature and time. The result is an increased susceptibility to intergranular corrosion and stress-corrosion cracking. The rates of progression of sensitization and stress corrosion cracking are thought to be closely linked to alloy microstructure, which is affected by material handling, composition, and temper among other factors. While methods exist for determining the level of sensitization at specific points in time, their inability to account for microstructural variability make them unable to predict remaining life in service. To reduce the risk of the use of AA5xxx alloys in marine environments, Luna proposes to develop a multi-modal measurement system that combines electromagnetic, ultrasonic, and x-ray diffraction techniques to provide a rich data set on the material’s microstructure that can be used in predictive models to determine the rate of progression of sensitization and stress corrosion cracking processes.

* Information listed above is at the time of submission. *

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