Characteristics of Cavitation-Erosion Damage with Amplitude in Seawater of 5052-O Al Alloy for Ship, 선박용 5052-O 알루미늄 합금의 해수 내 진폭 변수에 따른 캐비테이션-침식 손상 특성

The characteristics of cavitation-erosion damage with changes in the amplitude of 5052-O aluminum alloy for ships were investigated in a seawater environment. In the cavitation-erosion experiment, the cavitation environment was created using a vibration-generating device with a piezo-electric effect. The amplitudes of 5 μm, 10 μm, and 30 μm were created by changing the geometric shape of the cavitation horn. The resistance characteristics of cavitation-erosion damage were evaluated by weight loss and pitting area. The damaged surface was analyzed using scanning electron microscopy (SEM) and 3D optical microscopy. As the amplitude increased, the amount of damage and the area of the damaged surface increased, and the damage was concentrated at the center and edge of the specimen. The pit was created after the initial incubation period with increasing experimental time, and then the pits were merged to grow and propagate into craters, and eventually, the surface was detached and damaged. The cavitation-erosion damage after 30 minutes with amplitude of 10 μm and 30 μm was 1.48 and 2.21 times compared to 5 μm, respectively.