Laser Assisted Cold Spray Deposition for Additive Repair of Naval Structural Steels
Abstract
We propose the development of laser-assisted cold spray (LACS) deposition foradditive repair of load-bearing, high strength steel structures on naval vessels. The additive repair of steel structures in naval vessels is of critical importance for extending the life of surface and submarine warfare platforms. Degradation and failure mechanisms such as corrosion, erosion, wear, and fracture require the replacement of material to return the component to service performance levels. Unfortunately, fusion welding-based repair methods for high strength steels may deposit materials with highly unoptimized microstructures, compromised mechanical properties in the heat-affected zone of the underlying structural material, and even hyrdogen cracking after arc welding in wet environments. Cold spray deposition for additive repair could address many of these concerns, but its progress for high strength steels is still quite limited. Cold spray of ferritic and martensitic steels has not been widely performed due to the high strength of the powder particles found in these materials. Further progress for cold spray deposition of high strength steels will require an approach that moves beyond simply spraying asatomized powder through the standard de Laval nozzle. We propose the application of laser assisted cold spray (LACS) deposition for the additive repair of QTLA, heat treatable low alloy (HTLA), and other high strength steels. This research program will develop the LACS processing window for HY-80 and 4340 steels. The HY-80 and 4340 alloys will be investigated both because of their naval relevance and because of their distinct metallurgical differences. The mechanical properties, such as yield strength, elongation to failure, and impact energy, will be evaluated for LACS-produced steels with promising deposition efficiencies and microstructures. The thermal processing during LACS of these steels will be tuned so as to manipulate the microstructures that are formed. In addition, the potential of in situ annealing during LACS deposition for enhancement of material ductility will be carefully assessed during this program. Upon completion of this project, an initial recipe for additive repair through LACS of these steels should be identified based upon a combination of substrate, powder, and process conditions.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 10, 2018
- Source ID
- N000141812266
Entities
People
- Luke N. Brewer
Organizations
- Office of Naval Research
- United States Navy
- University of Alabama