||A cavitation erosion is the process based on an impact of pressure pulses on a material’s
surface caused by the phenomenon of cavitation. The term cavitation is defined as a phenomenon
of formation, growth and disappearance (implosion) of bubbles due to cyclic pressure variations
in a liquid. The cavitation initiators are embryos (cavitation nuclei with a size up to 50 μm), located
in the water or on wetted surfaces that lead to decreasing of the liquid ability to transfer tensile
stresses. The role of embryos is played by micro gas bubbles, fine solid particles, micro-organisms
or gas-filled pores on a surface of solid body embedded in a liquid. A rapid pressure drop occurring
within the liquid and a presence of cavitational kernel causes rupture the continuity of the liquid
and thus lead to the formation of steam-gas mixture areas, a so called cavitation bubbles.
A cavitation bubble may be filled with a gas, a vapor or a steam/gas mixture. A course of cavitation
depends on a cavitation type.
In the present work, a mechanism of cavitiational destruction of 99,7 % titanium tested
on vibrational and jet-impact valaboratory stands, is analyzed. Results of the cavitational resistance
evaluation of Ti99.7 titanium carried out on vibrational and jet-impact stands have revealed
different mechanisms of a cavitation destruction caused by various forms of cavitation. It was found
that a surface of titanium samples tested on the vibratory stand was covered by very large number
of microcracks which in a later stage of the research leads to the erosion of the material.
The cavitational destruction of Ti samples on the jet-impact stand is initiated by a plastic straining
of subsurface area, which in the further stage leads to an erosion represented by the detachment
of whole grains anda formation of deep pits on the material’s surface. Additionally, results
of conducted studies have confirmed the fatigue character of the cavitational destruction process.