SBIR-STTR Award

Localized corrosion of painted steel structures often initiates manufacturing or maintenance irregularities associated with metal joining, cutting or extreme forming. The restoration or introduction of highly controlled passive protection is viewed as a means of reducing or eliminating maintenance activities associated with painted steel structures. This project proposes the development of a portable, high quality and environmentally friendly system to provide localized laser cleaning, passive corrosion protection through laser cladding, and final polymer coating of steel structural features of limited spatial extent in one operation. This will be achieved by combining and optimizing existing laser-assisted processes to address the issue of metal passivization while controlling the burn-off of painted fabricated structures. A mechanical design for the portable system will be developed with a special emphasis on issues related with the deployment in a shipyard. This system will be benchmarked against currently used coating systems. Benefits Besides the manufacturing of new ship structures, the maintenance and repair of the Navy fleet is a well-known critical issue. The existing cooperation between Visotek, Fraunhofer and Bender Shipbuilding in other programs and the network of each of the involved parties, ensures dissemination of the results to other programs and stimulation of future programs. The US Air Force, Marine Corps, Army, NASA, Navy and major defense contractors such as Boeing and Lockheed Martin, shipbuilders including Bender and Northrop Grumman are all major stakeholders in the development of a portable laser system that cleans and provides corrosion resistance. The program, if continued in a Phase II will result in two products that have many derivative applications besides the one described in this proposal. First, the optics combining laser cleaning, laser cladding and sealing builds the base for use in body-in-white assembly and structures in the automotive, construction, aircraft and other military industries. The US Air Force, Marine Corps, Army, NASA, Navy and major defense contractors such as Boeing and Lockheed Martin, shipbuilders including Bender and Northrop Grumman are all major stakeholders in the development of a portable laser system that cleans and provides corrosion resistance. Secondly, the high power diode laser and the fiber laser are advanced laser systems that can either replace existing laser installation or open new markets due to their enhanced performance and low cost of ownership. Keywords metal passivization, corrosion resistance, diode laser, laser cleaning, laser cladding, epoxy based paint application, portable system

The Navy currently desires to extend drydocking cycles to 8 years. In order to do this, corrosion must be controlled and mitigated because it is the driving factor behind drydocking requirements. The proposed technology aims to significantly enhance localized corrosion resistance of contained areas of newly built ship structures as well as repair of used vessels. Localized corrosion of painted steel structures often initiates from manufacturing or maintenance irregularities associated with metal joining, cutting or extreme forming. The objective of this project is to develop a special scanning optics that performs metal passivization using laser cleaning, laser cladding and painting of weld zones in one operation. The primary applications will be derived once applicable standards and regulations are determined. The laser cleaning is a dry process complying with environmental regulations. The laser cladding and epoxy granulate based painting result in uniform and long lasting metal passivization. Together with advanced process development and qualification, this will lead to a portable system for use in any U.S. shipyard.

Keywords:
metal passivization, corrosion resistance, diode laser, fiber laser, laser cleaning, laser cladding, epoxy based paint application, portable laser sys