The Need

Manufacturers increasingly need to join stacks of very thin metallic foils and mixed‑thickness layers for applications such as electrification, electronics, and advanced manufacturing. Existing solid‑state joining methods—most notably impact welding and ultrasonic welding—struggle with these architectures due to required gaps, foil fragility, limited material combinations, long cycle times, and tool wear. There is a clear unmet need for a rapid, robust, solid‑state welding process that can join many thin layers simultaneously without pre‑gaps or extensive fixturing.

The Technology

OSU engineers have developed a modified impulse welding approach that enables gap‑free welding of stacked metal layers in a single, high‑speed event. A controlled mechanical impulse is delivered to the stack via an external driver, transmitting a shock through the layers that disrupts surface films and creates metallurgical bonds across interfaces. A sacrificial buffer layer protects the functional materials while efficiently transferring the impulse. The process is adaptable to different impulse generation methods, materials, and spot geometries.

Commercial Applications

• Electric vehicle battery packs
• Electronics and power devices
• Advanced manufacturing
• Multi‑layer current collectors and busbar assemblies

Benefits/Advantages

• Enables gap‑free welding of many thin foils and mixed‑thickness stacks in a single step
• Solid‑state process minimizes heat input and preserves material properties
• High throughput potential with very short cycle times compared to ultrasonic welding
• Improved electrical performance, demonstrated by large reductions in contact resistance