Researches to Find New Resistible Materials Against Erosive Vortex Cavitation and Compound Erosion

The compound erosion，the coupling of abrasive wear and cavitation erosion，on affects the destruction of materials in many subtle ways。In this project，our studies are focused on the severe action of the erosion and the wear on accelerated cavitation，flow cavitation and impingement jet cavitation，which are significantly affected by various material properties and liquid qualities，and also are focused to clarify the mechanism of the compound erosion on metal surfaces，where unsteady vortex cavitation predominantly takes place in high speed multiphase fase fs in turbomachinery.From these studies，we find the useful methods of preventing or overcoming such compound erosion，by using resistant materials and protective coatings。In order to make clear the development processes with test time and to evaluate the results，the surface deformation and the micro-scaled fracture on the eroded surface with respect to the cavitation aspects，through a scanning electron microscope as well as a high-speed camera.

The compound erosion, the coupling of abrasive wear and cavitation erosion, on affects the destruction of materials in many subtle ways. In this project, our studies are focused on the severe action of the erosion and the wear on accelerated cavitation, flow cavitation and impingement jet cavitation, which are significantly affected by various material properties and liquid qualities, and also are focused to clarify the mechanism of the compound erosion on metal surfaces, where unsteady vortex cavitation predominantly takes place in high-speed multiphase flows in turbomachinery. From these studies, we find the useful methods of preventing or overcoming such compound erosion, by using resistant materials and protective coatings. In order to make clear the development processes with test time and to evaluate the results, the surface deformation and the micro-scaled fracture on the eroded surface with respect to the cavitation aspects, through a scanning electron microscope as well as a highーspeed camera.