TWI Frequently asked questions
by Chris Otter
As well as simple crimping processes, ultrasonic and resistance welding are used. When compared with soldering, the key benefits of these processes are reduction both in the materials costs and health & safety and disposal costsassociated with solders and fluxes.
Resistance and ultrasonic welding work best for this application if a saddle-shaped electrode/sonotrode is used to prevent the strands from splaying as the weld is made. The geometry of the saddle feature must be suitable for thewire diameter, to prevent the electrode/sonotrode from touching down either side of the wire. If this happens, welding current (resistance welding) will have a secondary path to follow, resulting in a cooler weld. In the case ofultrasonic welding, the vibration energy will be absorbed into the machine anvil rather than being concentrated through the workpiece.
