Study of Comparative Resistance to Cavitational Erosion of Material Samples and Coatings in the Hydraulic Machine Flow Sections

The material resistance to cavitation is studied experimentally in the flow sections of hydraulic machines. A brief review of existing normal and accelerated testing methods of the material resistance to cavitation erosion is presented. The testing technique is based on the ultrasonic cavitation method. The test bench design is described. The samples of various grades of steels, as well as of polymers and rubber coatings of different thicknesses are investigated. Test results characterizing comparative resistance to cavitation of materials and coatings are presented as the relationships between the sample mass loss and the rate of mass loss for different materials and testing time. Photo images of the samples subjected to cavitational erosion are presented. Conclusions are made about the applicability of different materials and coatings for manufacturing the working parts of vane pumps and water turbines.

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