What factors determine the final welding strength of ultrasonic metal welding?

1. Ultrasonic Amplitude (Vibration Output)
Higher amplitude brings stronger friction heat and deeper molecular fusion, improving shear & tensile strength.
Excessively high amplitude causes over-welding: metal extrusion, foil piercing, thin material cracking, which reduces strength instead.
Low amplitude leads to insufficient friction, cold weak welds that peel easily.

2. Welding Energy / Welding Time
Longer welding time or higher total energy accumulates enough friction at the metal interface to break oxide films and form metallurgical bonding.
Insufficient energy: incomplete fusion, low pull force, unstable batches.
Over-energy: severe plastic flow, thin foils break, brittle bonding interface.
Digital energy closed-loop control ensures identical energy output every weld for stable strength.

3. Clamping Pressure (Air Cylinder Force)
Appropriate pressure makes two metal surfaces fully contact under ultrasonic vibration to transfer friction energy evenly.
Too little pressure: loose contact, weak friction, inconsistent weld strength.
Too much pressure: excessive metal extrusion, thin tabs torn, the welding layer becomes too thin to bear tension.
Pressure adjustable via precise pressure regulating valve for multi-layer stacks, busbars and wiring harnesses.