Cavitation erosion of silver plated coatings considering thermodynamic effect

Cavitation often occurs in inducer pumps of space rockets. Silver plated coating on the inducer liner faces the damage of cavitation. In this study, we carried out cavitation erosion tests using silver plated coatings with different thermodynamic parameter at a constant cavitation number. Then we carried out cavitation erosion tests using some liquid with the same thermodynamic parameter and cavitation number as liquid oxygen condition. Thermodynamic parameter Σ proposed by Brennen was used as a thermodynamic parameter. The fluids used for the cavitation erosion tests were water, ethanol and hexane. We discussed the relation between thermodynamic parameter and mass loss rate, and the relation between acoustic impedance and mass loss rate.

► Cavitation erosion tests were carried out on silver plated coatings.
► Hardness test were also carried out by using a Shore hardness tester.
► Hardness of silver plated coating does not change at temperature from 303 K to 403 K.
► The thermodynamic effect appeared at Σ of 100 m/s3/2 or more.
► The mass loss rate can be evaluated based on acoustic impedance.