The word ‘cavitation’ does not appear in Wells, nor in ReVo, nor in Sonja. It does occur in Benson and Vikivortaro. However, Benson gives ‘kaviĝ(ad)o’, while Vikivortaro gives ‘kavitacio’. However, PIV does not recognize ‘kavitacio’, but PIV is perpetually a little behind the times, is it not? So, should be go with Benson, or Vikivortaro, or something else?
edit: I neglected to check Vikipedio. I see that it has 'kavitacio', so maybe that is the way to go, after all.