Application of spherical nanoindentation to determine the pressure of cavitation impacts from pitting tests

This article focuses on the use of spherical nanoindentation measurements to estimate the pressure of cavitation impacts and its statistical distribution. Indeed, nanoindentation techniques are supposed to represent an effective tool in this field due to the similarities between substrate deformation under liquid impact and indentation testing. First, nanoindentation experiments were used to extract the mechanical parameters of a Nickel-Aluminum-Bronze alloy; second, pitting tests were performed at different operating pressures, and the geometrical characteristics of the pits were measured; and finally, the spectra of impact pressure and loads responsible for material erosion were obtained by coupling the findings of indentation tests with the analysis of pitting tests. Results assessed the capability of the proposed methodology to quantify the hydrodynamic aggressiveness of the cavitating flow. This procedure, which assumes the material itself as a sensor that is able to detect the impact loads, could represent an alternative solution to pressure transducers in estimating the cavitation intensity.