Laser Induced Rectangular Microstructures for Surface of Cavitation Erosion Resistance

In the design of hydraulic machines, the application of surface treatments is essential to improve the cavitation erosion resistance of components. In this paper, the cavitation erosion behavior of rectangular microstructure surfaces was studied. Before cavitation erosion experiments, the surface of 1060 high purity aluminum plate was processed by laser microfabrication method to generate rectangular microstructures with special groove depth, groove width and different periods. The cavitation tests were carried out using a commercially available ultrasonic vibratory apparatus. Before and after the cavitation erosion experiments, specimens with rectangular microstructures were measured for calculating the average cavitation erosion losses with analytical balances, analyzed for exploring cavitation erosion mechanisms using numerical simulation, scanning electron microscopy and optical microscopy. The results showed that rectangular microstructure surfaces, compared to the smooth surfaces, have better cavitation erosion performance, and its period, as an important parameter of the microstructure configuration, was a factor affecting cavitation erosion resistance. The cavitation erosion resistance mechanisms of rectangular microstructure surfaces were lower vapor volume fraction and smaller pressure fluctuation, which will not lead to the contraction and collapse of the bubbles.