Ultrasonic Cavitation Processing Research Laboratory

Iakovos Tzanakis


For the first time systematic studies showed that the governing mechanisms of sono-fragmentation are the shock waves emitted from the imploding cavitation bubbles.

Results showed that in the case of a single bubble collapse, the produced shock wave pressures in the range of 20-40 MPa are responsible for instantaneous fragmentation of the intermetallics. Whereas, the shock pressure generated from repetitive acoustic cavitation cloud collapses surged up to 1.6 MPa inducing fatigue stresses within the crystal leading to eventual fragmentation.

In addition and for the first time high-speed filming captured the dynamic interaction of shock waves with floating intermetallic particles that led to their fragmentation. Repeated fragmentations are induced as the crystals recirculate with the acoustic streaming generated from the vibrating probe at 20 kHz.

Contactless breakage observed in both fixed and floating crystals (see videos)