Description: NASA Langley Research Center (LaRC) and Lockheed Martin (LM) are collaborating on advanced forming of Friction Stir Welded (FSW) blanks to support future Cislunar/Lunar Infrastructure and Capabilities under the STMD 2022 Announcement of Collaboration Opportunity (ACO). LM and NASA LaRC have been investing in FSW and advanced forming technologies for large metallic structures with internal resources for the past decade. Under the ACO Project entitled Friction Stir Adjoined Blank-Forming on Revolutionary Machinery (FAB-FORM), LM and NASA LaRC are pursuing the use of spin/flow forming and high-energy (explosive) hydroforming for subscale manufacturing demonstrations to produce dome structures from FSW blanks. FSW blanks offer larger blank sizes than commercially available in single plates, enabling advanced forming of large structures. Formed domes and cones are almost always the critical path for producing pressurized spaceflight hardware such as propellant tanks, launch vehicle fuel tanks, and crew vehicles. Spin/flow forming and explosive hydroforming have significant potential to enable NASA missions to be ready for flight in a shorter time frame. Large explosive hydroformed shapes are extremely valuable to future NASA initiatives in cislunar space and lunar surface. Both NASA and LM are seeking to advance explosive hydroforming technologies to provide a lower cost, reduced mass, and shorter lead time for large metallic bulkheads, domes, and cones to accelerate deployment of new lunar assets for NASA and the commercial space sector. Additionally, spin/flow forming on the NASA LaRC VUD-600 will enable investigation of spin/flow formability of FSW blanks. Mechanical properties and metallurgical characterization of the subscale demonstration parts will be conducted to evaluate potential service performance for larger scale commercialization. The goal of the advanced forming technologies is to eventually provide the capability to scale up to > 5-meter diameter applications.

Benefits: Lead times for commercial spin forming in the US for 2–5-meter domes are > 9 months due to existing backlogs. Currently, spin forming is not available for domes > 5 meters. Spin forming trials on the VUD-600 for FSW blanks may provide a pathway for spin forming of larger FSW blanks without the need for complex tooling. Explosive hydroforming offers a secondary manufacturing path to reduce lead time by 50% or more compared to existing commercial spin forming capabilities, which is a significant bottleneck for crew modules and pressure vessel domes. Explosive hydroforming may enable dome and other complex geometries > 5 meters in diameter to be formed using FSW blanks. Explosive hydroforming requires minimal tooling, further reducing cost and lead time, while offering greater flexibility. Furthermore, explosive hydroforming offers the ability to form in a -T3 temper, eliminating the need for solution heat treating and quenching of the formed part. This eliminates the infrastructure need for large-scale drop bottom furnaces and reduces production cost by ~$50K per article.