Cavitation erosion of silver plated coatings in a low-temperature environment

It is well known that cavitation occurs in inducer pumps used for space rockets. The silver plated coating on the inducer liner faces erosion damage. In this study, we carried out cavitation erosion tests on seven silver plated coatings with the stationary specimen method using a vibratory apparatus. We analyzed the erosion behavior of these coatings and discussed their erosion resistance. The erosion resistance of silver plated coatings can be evaluated in terms of material hardness and was ranked between pure aluminum and pure copper. Moreover we carried out erosion tests using the vibrating specimen method in deionized water, liquid nitrogen and ethanol for the silver coating which showed the highest erosion resistance in the stationary specimen method. We found that erosion occurred in low-temperature ethanol, but not in liquid nitrogen.