Home / Industries / FSW vs Brazing for Cold Plates
Comparison
Friction Stir Welding vs Brazing for Liquid Cooling Cold Plates
Liquid cooling assemblies fail where they are joined. A friction stir welded closure seals the plate without braze foil, a furnace cycle, or a gasket.
In short: A friction stir welded cold plate pairs a machined or extruded channel plate with a friction stir welded closure. The joint is solid-state, hermetic, and parent-metal-class in strength, made without braze foil, a furnace cycle, a gasket, or a leak path.
Side by side
Friction Stir Closure and Brazed Plate Compared
| Feature | Friction stir welded closure | Brazed plate |
|---|---|---|
| Seal | Hermetic, solid-state joint with parent-metal-class strength | Integrity depends on the braze joint wetting properly |
| Furnace step | None | Adds a braze cycle, fixturing, and lead time |
| Braze foil or gasket | Neither is needed | Foil is required, and gasketed designs add a leak path |
| Channel geometry | Permits geometry that a brazed stack-up cannot hold | Limited by what the stack-up can hold |
| Pressure cycling | Survives pressure cycling | Leak-test failures and scrap erode yield |
| Alloy choice | Alloys that crack under fusion welding are routine, so choice follows performance | Constrained by what can be brazed |
Where it fits
When a Friction Stir Closure Makes Sense
- Leak-test failures and scrap on brazed or gasketed cold plates.
- Thermal performance no longer keeping up with power density.
- Recalls or warranty cost tied to a leaking or cracked joint.
- Gun-drilled or bonded plate designs limiting channel geometry.
- A braze cycle adding a furnace step, fixturing, and lead time.
What LeapFast builds
Thermal Structures Built With Friction Stir Welding
LeapFast builds liquid cooling cold plates, heat exchangers as a brazed-plate replacement, EV and battery trays with integral cooling, and power electronics baseplates. Often the channel design can stay as it is and only the closure changes, which is the least disruptive way to trial the process.
Questions
Cold Plates, Answered
How does a friction stir closure compare with a brazed plate?
A friction stir closure is a solid-state joint with parent-metal-class strength and a hermetic seal, produced without a furnace cycle. Brazing adds a thermal cycle, fixturing, and a joint whose integrity depends on wetting.
Can LeapFast match my existing channel design?
Usually the channel design can stay and only the closure changes, which is the least disruptive way to trial the process. Send a drawing and LeapFast will say so.
What volume can LeapFast support?
Development and prototype now, with production scaling through equipment and university partners. Tell LeapFast the volume and the date and you will get a straight answer about the ramp.
Can friction stir welding join aluminum to copper?
Yes. Aluminum-to-copper joints remove bulky mechanical transitions and let the designer pick the right alloy for each side.
Do I need to buy a friction stir machine?
No. You send LeapFast a drawing, LeapFast builds the part, and the part is shipped to you. LeapFast does not sell machines.
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.