Different methods of measuring synergy between cavitation erosion and corrosion for nickel aluminium bronze in 3.5% NaCl solution

摘要

In order to understand the combined detrimental effects of cavitation erosion and corrosion in seawater on a conventional marine alloy, nickel aluminium bronze, five different methods were employed to obtain synergism. The experiments were conducted using an ultrasonic vibratory horn functioning at 19.5 kHz frequency and 80 mu m +/- 0.2 mu m peak-to-peak amplitude. The test methods used to obtain the synergy included gravimetric mass loss, volumetric, mean depth of penetration rate, and potentiodynamic polarization techniques. The cavitated surfaces were microstructurally characterized via scanning electron microscopy. NAB was seen to suffer from selective phase attack, resulting in increased material removal especially in the presence of corrosive environment. Synergism was found to range between 6 and 74% under different test methods.