N092-093 TITLE: 3D Surface Mapping of Corrosion on Complex Curved Surfaces

TECHNOLOGY AREAS: Air Platform, Materials/Processes

ACQUISITION PROGRAM: PMA-265 F/A-18 Super Hornet, Growler

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), which controls the export and import of defense-related material and services. Offerors must disclose any proposed use of foreign nationals, their country of origin, and what tasks each would accomplish in the statement of work in accordance with section 3.5.b.(7) of the solicitation.

OBJECTIVE: Develop and demonstrate an efficient method of generating high-resolution 3D topographic maps of corrosion damage on complex curved and interior surfaces.

DESCRIPTION: Corrosion damage on flight critical structural components has a significant adverse impact on fleet readiness and total ownership costs. Much of the costs and inconvenience of corrosion damage repair can be traced to uncertainty over the severity of corrosion necessary to cause a significant reduction in the fatigue life of a damaged component. For any quantitative assessment of corrosion severity, surface topology data with sufficient resolution to capture the important characteristics of the features that cause fatigue cracking is required. To address these issues, NAVAIR has recently concluded a research program to investigate and quantify the fatigue life reduction due to corrosion on high-strength steels. The result of this research is an Equivalent Stress Riser (ESR) model for predicting the remaining fatigue life of AF1410 steel components with surface corrosion damage. The most critical input into the ESR model is the availability of high-resolution 3D topographic maps of the corroded surfaces. The research program successfully used commercial White Light Interferometry (WLI) equipment to generate corrosion maps for small flat test plates and dental impression corrosion replicas. However, most high-strength steel airframe components such as landing gear and arrestment shanks have complex curved and cylindrical surfaces with a variety of fillets and transition radii. Also, corrosion often occurs on the inside surfaces of hollow cylindrical sections. Current WLI techniques are not well suited for mapping surfaces with complex curvatures. Therefore, a need exists for the development of an innovative capability to efficiently perform high-resolution 3D corrosion surface mapping on large high-strength steel airframe components and replicas of corroded surfaces. General requirements for an improved surface mapping capability include: a) ability to create corrosion maps from complex curved surfaces, to include inner cylindrical and tapered surfaces, interior and exterior fillets and dental impression corrosion replicas; b) minimum lateral resolution of 2 microns and minimum vertical resolution of 0.1 microns; c) automation to minimize the amount of operator interventions to reposition part for scanning, reset instrument parameters, etc.; d) minimize the amount of manual post acquisition image stitching and filtering necessary to create a complete image map; e) minimize the computation and data storage requirements for manipulating large image map files.

PHASE I: Develop a theoretical approach for conducting 3D corrosion mapping of curved surfaces on large airframe components and dental impression corrosion replicas. Propose a conceptual design for a prototype system to perform 3D mapping of curved surfaces that has the potential to meet the stated requirements, and demonstrate feasibility.

PHASE II: Develop the detailed design and construct a prototype of the system proposed in Phase I. Demonstrate the ability of the prototype to meet the stated requirements by performing 3D surface scans of service corroded landing gear and arresting shank components, and dental impression corrosion replicas.

PHASE III: Fully develop the prototype system into a commercial product. Transition the technology for use in the NAVAIR Fleet Readiness Centers (FRC)�s and for commercial applications.

PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: The prototype 3D surface mapping capability demonstrated for the Department of Defense has broad commercial application in the area of Non-Destructive Inspection of the surface conditions of large, geometrically complex engineered structural components. Potential applications include: inspection of piping in the petroleum and petrochemical industry; inspection of piping in Navy ships and shore facilities; commercial airlines; etc.

REFERENCES:
1. Rusk, D.T., Hoppe, W., Braisted, B. and Powar, N., "Corrosion-Fatigue Life Prediction using an Equivalent Stress Riser Model," 11th Joint NASA/FAA/DoD Conference on Aging Aircraft, Phoenix, AZ, 21-24 Apr. 2008.

2. Hoppe, W, Scott, O., Braisted, B., Abfalter, G., Pierce, J. Burke, E., Kuhlman, S., Frock, B. and Ko, R., "Navy High-Strength Steel Corrosion-Fatigue Modeling Program," UDR-TR-2007-00039, University of Dayton Research Institute, Dayton, OH, Oct. 2006.

3. Rusk, D.T., Pierce, J., Hoppe, W., Lancaster, B., Actis, R. and Szabo, B., "Analysis and Testing of Fleet Corroded F/A-18C/D Arrestment Shanks," NAWCADPAX/TR-2008/9, Naval Air Warfare Center Aircraft Division, Patuxent River, MD, 20 June 2008.

4. Albertazzi, G.A., Viotti, M.R. and Dal Pont, A., "A White Light Interferometer for inner cylindrical surfaces," Proceedings of SPIE, the International Society for Optical Engineering, Applications: San Diego, CA, 16-17 Aug. 2006.

5. Holme, B. and Lunder, O., "Characterization of pitting corrosion by white light interferometry," Corrosion Science, Vol. 49, No. 2, 2007, pp. 391-401.

KEYWORDS: Corrosion; Surface Imaging; Topology; Curvature; Fatigue; Maintenance

** TOPIC AUTHOR (TPOC) **

DoD Notice:   Between April 20 and May 17, 2009, you may talk directly with the Topic Authors to ask technical questions about the topics. Their contact information is listed above. For reasons of competitive fairness, direct communication between proposers and topic authors is not allowed starting May 18, 2009, when DoD begins accepting proposals for this solicitation.

However, proposers may still submit written questions about solicitation topics through the DoD's SBIR/STTR Interactive Topic Information System (SITIS), in which the questioner and respondent remain anonymous and all questions and answers are posted electronically for general viewing until the solicitation closes. All proposers are advised to monitor SITIS (09.2 Q&A) during the solicitation period for questions and answers, and other significant information, relevant to the SBIR 09.2 topic under which they are proposing.

If you have general questions about DoD SBIR program, please contact the DoD SBIR Help Desk at (866) 724-7457 or email weblink.