The ability of using the cavitation phenomenon as a tool to modify the surface characteristics in micro- and in nano-level

The aim of this paper is to investigate the possible application of the cavitation phenomenon as efficient method to modify the surface properties (e.g. the surface roughness) in the nano- and micro-levels. Aluminum alloy (AlSiMg) specimens were subjected to high speed submerged cavitating jets under various working conditions, for short time periods between 15 and 30 s. The force generated by the cavitating jet is employed to modify the surface roughness of the specimen. The target surface was analyzed with optical microscopy, white light interferometry, atomic force microscopy (AFM) and also with electrostatic force microscopy (EFM). The results show the possibility to use the cavitation bubbles as a nanofabrication method e.g. for shotless surface peening. With AFM, the deformation mechanism and the formation of planar or wavy slip were also investigated. EFM shows that the changes in the surface roughness also have a strong influence on the electrostatic field above a biased sample.