Investigation of Cavitation Damage Progress in the Incubation Period Using Stepwise Erosion and Image Process Techniques

Abstract

Cavitation damage process of stainless steel during the incubation period was detected and evaluated using stepwise erosion technique and image processing. The damage experiments were conducted using the vibratory test rig. The scanning electron microscope images at different locations on eroded surface using stepwise technique were presented. In addition, the surface roughness was measured with the testing time. Discrete wavelet transforms and fractals had been adopted to extract the relevant features. It was found that the feature parameters: Shannon entropy, energy loss, fractal dimension and intercept show a fairly linear increase with the testing time. It was also observed that the feature parameters have reasonable correlations with the roughness parameters.