Linear Vibration and Orbital Welding

Linear vibration and orbital welding are essentially the same technique with the obvious difference being that one oscillates back and forth in a linear motion and the other oscillates in an orbital path. These techniques are applicable to parts that are larger (200-1500 mm) than those handled by ultrasonic welding. Large automotive under the hood air boxes and manifolds are vibration welded from PA (nylon). Recently, high-temperatnre polyamide oil sumps have been welded with this technique. 

For linear vibration welding the two components are pressed together with a pressure of 0.5-14 MPa oscillated at a frequency of 100-500 Hz (120 and 240 Hz are industry standard freqnencies) and an amplitude of 0.5-5.0 mm for a times of the order of 10 s. The welding process is described as four stages  

The initial solid friction stage where there is frictional heating, but not penetration or approach of the two components. 

The transition stage where the surfaces start to melt and flow, penetration increases nonlinearly as a function of time. 

The steady-state phase where penetration joint is approximately a linear function of time. 

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