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Technology explainer
What Is Bobbin Friction Stir Deposition (B-FSD)?
A solid-state additive process, developed at NASA and exclusively licensed to LeapFast, that builds large metal structures without melting the metal.
In short: Bobbin Friction Stir Deposition (B-FSD) is a solid-state additive manufacturing process. A self-reacting bobbin tool builds up metal in passes without melting it, so the finished structure has a refined microstructure with no solidification porosity or hot cracking. It runs on existing friction stir welding equipment.
How it compares
B-FSD Next to Forging, Casting, and Melt-Based Additive
| Process | Needs a die or pattern | Melts the metal | What to know |
|---|---|---|---|
| B-FSD | No | No | Builds net-shape structures from your drawing, with no die and no queue behind one. |
| Forging | Yes, a forging die | No | Multi-month lead times, and quantities below a forge's economic minimum are hard to get quoted. |
| Casting | Yes, a pattern or mold | Yes | Solidification porosity can limit strength and fatigue life. |
| Melt-based additive | No | Yes | High-strength alloys can crack, and melting can leave porosity. |
Why it matters to you
What B-FSD Means for Your Program
If a forging die is gating your schedule, B-FSD removes the die from the plan. If your part is too large to cast, it is built one pass at a time, so size is not the limit. And because the metal never melts, you avoid the defects that come from melting.
LeapFast applies B-FSD to aluminum domes and bulkheads, rings and barrel joints, cryogenic tanks, and repair or feature additions to structures already in service, for aerospace, space, and naval programs.
Questions
B-FSD, Answered
What does B-FSD stand for?
B-FSD stands for Bobbin Friction Stir Deposition. It is a solid-state additive manufacturing process, which means metal is built up without being melted.
Who developed B-FSD?
B-FSD was developed by Zachary Courtright at NASA Marshall Space Flight Center. LeapFast holds an exclusive license to the NASA process, which is covered by US Patent 12,157,179 B1.
How is B-FSD different from friction stir welding (FSW)?
Both use friction stir tooling and both work below the melting point of the metal. FSW joins pieces of metal together, while B-FSD builds up new metal, layer by layer, to form a structure. B-FSD runs on existing friction stir welding equipment.
Is B-FSD the same as additive friction stir deposition?
They belong to the same family of solid-state, friction-based additive processes. B-FSD is the NASA-developed bobbin-tool version that LeapFast is licensed to use.
Do I need to buy equipment to use B-FSD?
No. You send LeapFast a drawing, LeapFast builds the part, and the part is shipped to you. LeapFast does not sell machines.
What can B-FSD make?
LeapFast applies B-FSD to net-shape aluminum domes and bulkheads, rings and barrel joints, cryogenic tanks, and repair or feature additions to existing aluminum structures, for aerospace, space, and naval programs.
Got a Part Holding Up Your Program? Send It to Us.
A drawing, a STEP file, or a sketch and a size is enough. You will hear back within 3 business days.