A study of cavitation erosion on engineering materials

In this study, cavitation erosion tests were conducted on different materials such as pure aluminium (99% aluminium) and 1045 steel which were used as "vibratory" specimens, whereas untreated 6082 aluminium alloy, 304 stainless steel and 4340 steel were used as "stationary" specimens. A first set of tests was conducted using only tap water where a lower wear rate was observed. On the other hand, a second set of tests was carried out adding silicon carbide particles to the tap water which led to increase of the erosion wear rate. It helped to evaluate the performance of all the tested materials at different testing conditions.High speed camera was used to analyse the bubble formation in the radiating surface of the horn made of 2024 aluminium alloy. In these videos, it was possible to observe that the bubble formation was similar to the cone-like bubble structure (CBS) observed in other cavitation studies. Additionally, high speed videos were obtained as abrasive particles were used to conduct the tests. In these, it was possible to observe how abrasive particles were moving along the two surfaces, staying in the clearance to cause higher wear damage on both surfaces. The "stationary" specimen was located at a 1. mm distance with respect to the position of the "vibratory" specimen which was attached to the radiating surface. Optical microscopy was used to identify the wear mechanisms which were characterized by a pitting action when only tap water was used whereas some scratches and irregular indentations similar to those observed in abrasive wear were seen on the surfaces with abrasive particles.