What is Vibration Welding?

Linear vibration welding physically moves one of two parts horizontally under pressure, creating heat through surface friction that melts and welds the parts together. Compared to ultrasonic welding, vibration welding operates at much lower frequencies, higher amplitudes and much greater clamping force. Linear vibration welding is designed with electromagnetic heads that eliminate wear and lubrication associated with bearing surfaces.

Welding stages include: 1) Solid Friction; 2) Transition; 3) Optimum Joint Strength; 4) Cooling.

1. Solid Friction

Linear motion of one part against another generates friction between the two surfaces, producing heat at the joint.

2. Transition

The parts begin to melt at the joint. High heat generation from the high shear rate causes further melting and a thicker melt layer. As the melted layer thickens, the viscosity increases and the shear rate decreases resulting in less heating. Pressure on melting parts promotes fluid flow to create the joint.

3. Optimum Joint Strength

The weld process is discontinued when the joint has reached its optimum strength. This is indicated when the parts melt at a rate equal to the outward flow rate at the joint.

4. Cooling

With pressure maintained on the joint, the material re-solidifies, forming a molecular bond.