SBIR-STTR Award

The objective of this proposed effort is to develop cost-effective fabrication technology for ultra-light steel structures using metal foam technology. Ultra-light metals, materials with densities less than 50 % that of bulk alloys offer significant structural advantages in terms of compressive strength- and stiffness-to-weight ratios for both military and commercial structures. Such materials have also been found to offer excellent crash protection, flame retardation, vibration damping and blast protection. UltraClad Corporation intends to build upon steel metal foam technology developed at Fraunhofer Institute which have been shown to offer promise in meeting program objectives. In Phase I concepts for low cost fabrication/manufacturing like Hot isostatic pressing (HIP), P/M techniques, and foaming additions such as strontium carbonate and carbon will be evaluated as candidate technologies. In Phase II a material mechanical and physical property data base sufficient for engineering design studies will be developed, and methods identified in Phase I for joining ultra-light steel materials and fabricating engineering structures will be demonstrated.

Phase I results were extremely positive and a plan for Phase II follow-on work is hereby presented. Foam core steel sandwich panels, based on Fraunhofer Institute technology, were successfully demonstrated in subscale during Phase I. The process path of HIP plus foaming and HIP plus deformation (rolling) and foaming produced panels superior to all other steel foam process methodologies thus far explored. The following issues were identified for further effort, understanding, and improvement in Phase II: Improvement in pore size distribution, improved theoretical understanding of the mechanism of steel foaming, foam demonstration and scale-up of steel foam panels via a HIP plus roll plus foam approach and fabrication of a protoype naval vessel door with Bath iron Works. The properties of steel foams and steel foam sandwiches suggest numerous potential applications in advanced ship designs: o Hulls using steel foam sandwiches with steel face sheets o Elevator platforms o Pontoons, docks, buoys, cargo-loading decks, life rafts o Fire doors, bulkheads, partitions, floors, cabin interiors o Lightweight, damage-tolerant rapid-deployment pallets and cargo containers o Blast deflectors and pyrotechnic lockers o Antenna platforms o Deck ramps, hatch covers, stern gates o Lightweight ladders, scaffolding, and furniture