抄録
The ceramics, which can withstand corrosion, being heat and abrasion resistant, are drawing the attention of engineers, as they may be successfully applied to the parts of hydraulic machines where cavitation cannot be avoided. However, basic information on the behavior of these materials under cavitation attack is still lacking. In order to select the most suitable testing apparatus for obtaining this information, cavitation erosion tests on ceramics were conducted using three different apparatus, namely a water tunnel, a vibratory unit and a vibratory unit with a stationary specimen. In the water tunnel, the intensity of the cavitation attack was so low and it took such a long time to obtain a test result, that it was judged unsuitable for an accelerated testing. In the vibratory unit, the test results were affected by the vibration amplitude not evenly from a material to another. The vibratory unit with a stationary specimen was selected as the most suitable testing apparatus for ceramics as it is free from these disadvantages. Regarding the preparation of the specimens, it was found that the weaker the material, the thicker specimen should be used. Using the established testing method, cavitation erosion tests were conductedd on six different ceramics and it was revealed that the resistance of ceramics is closely related to their fracture toughness rather than their hardness.
