Ultrasonic Welding
Ultrasonic welding is a high-frequency friction welding process where mechanical vibrations break up oxide and adsorption layers and create a tight bond. It's especially suited for thin materials.
Physicochemical Mechanism of Action
Ultrasonic welding uses high-frequency vibrations (mostly between 20 kHz and 5 MHz) that bring mechanical energy into the workpiece. This energy destroys oxide and adsorption layers on the surfaces of the materials being joined – that allows a direct, strong bond.
Metallurgical Relevance & Welding Risks
This process is ideal for thin sheets because it offers high bond quality and low heat input. But: too high ultrasonic power can cause local overheating, which leads to cracks or distortion. An inaccurate welding direction also gives uneven bonding and weak spots.
Workshop Practice & Instructions
For successful ultrasonic welding:
• Clean and polish the materials before welding.
• Set the ultrasonic device correctly – match frequency and amplitude to the material.
• Control the welding direction and speed precisely so the bond becomes even.
• For thin materials, use low pressure and short heat input.