Cavitation erosion resistance of plastics

Cavitation erosion tests were carried out for plastics, i.e. for epoxy resin, polypropylene, high-density polyethylene and polyamide 66, and the relation between cavitation erosion resistance and the mechanical properties was examined. Cavitation erosion resistance of plastics ranges between half and 30 times that of carbon steel. The cavitation erosion of plastics was caused by fatigue fracture similar to metals. Since plastics have relatively small acoustic impedance, the impact loads applied by bubble collapse become very small. Therefore, the resistance and the incubation period of cavitation erosion of plastics can be evaluated in terms of bubble collapse impact energy and the strain energy obtained from the fatigue strength.