Loughborough team helps pioneer ultrasonic additive process

Upcoming advanced-manufacturing processes will enable engineers to design and create products that have passive or active devices embedded within them. The characteristics of such products will not only enable them to be interrogated in the field, but also modified while in use.

One such manufacturing process is ultrasonic consolidation, an additive-manufacturing technique that is based on the use of ultrasonic technology to weld a sequence of metal foils.

In practice, the technique exploits both surface-friction and volume-plasticity softening effects to create a join between two layers of metal foils through the use of a rotating cylindrical sonotrode.

When the sonotrode is excited by a piezoelectric transducer, it oscillates at ultrasonic frequencies as it rolls across the strips of metal foil, imparting energy to the top strip and causing it to vibrate by tens of microns.

The combination of the pressure imparted onto the foils by the clamping force of the sonotrode and the ultrasonic vibration of the foil results in friction, which creates the solid-state weld between the two strips. The process is then repeated layer by layer until a solid component has been created. CNC contour milling is then used to create the shape that is required from the material.