Evaluation of Anti-Cavitation Property of Coating Materials for Structural Repair

Abstract

Structural repair by polymer coating has been recently attracted attention to pumps in water plants because of its simplicity. The performance of coating material is simply evaluated by cavitation resistance, but it should be considered under loading condition for application to existing structures. In this study, damage of coating material due to cavitation is observed with various loading conditions. Epoxy resin is selected as coating material on aluminum base. First, tensile and shear tests of the coating material is conducted with different way of coating angles to obtain fracture stresses. Second, a conventional cavitation erosion test is modified using a tensile jig developed to conduct a tension-cavitation test. As a result, the tensioncavitation test resulted in much severer damage in short time than conventional cavitation erosion test even though the stress on the coating material is more than 10 times smaller than the fracture stresses.