Comparative investigation of ultrasonic cavitation erosion for three materials in deionized water

Abstract

To investigate the response of material to cavitation erosion, a comparative work was carried out on three materials, aluminum, copper alloy and titanium. Ultrasonic cavitation erosion was produced as the specimen was submerged in the deionized water. Within a cavitation erosion period of 120 min, the cumulative mass loss was measured at certain time intervals. Surface structure and cavitation damage patterns were observed for the three materials. Microhardness was measured and compared. The results indicate that the cumulative mass loss of aluminum is the highest among the three materials, while the slightest material removal is associated with titanium, which is still in the initial stage of cavitation erosion after 120 min of cavitation erosion. The surface of the aluminum specimen is eroded rapidly after the cavitation erosion commences. Large erosion pits dominate the eroded surface as the cavitation erosion progresses. The surface of the titanium specimen manifests needle-like erosion pits and cleavage cracks. Even at the later stage of the cavitation erosion, non-eroded surface elements are identifiable. The cavitation erosion pattern on the copper alloy specimen surface is related to the twin-phase crystal structure and large erosion pits are produced at the later stage of cavitation erosion. The highest resistance to the cavitation erosion of titanium is related to the close-packed hexagonal structure and the weak slip effect associated.