Assessment of Ultrasonic Cavitation Corrosion Bench Tests

Several ultrasonic bench rigs are widely used in the engine coolant industry for cavitation corrosion tests. These tests are focused on the qualification of coolants formulated to minimize cavitation corrosion. Standardized metal test “buttons” of different materials are used for that purpose. Traditionally these cavitation corrosions tests are run for a specified period of time. At the end of the test the amount of mass removed from coupons due to cavitation is a direct reflection of the cavitation corrosion performance of the additive. However, results can show wide scatter and inconsistencies depending on the ultrasonic probe manufacturer, testing lab, horn type, dial setting level and probe instability. Therefore, a way of quantifying the cavitation intensity of these various designs was clearly called for to establish a standardized test and recommendation to be utilized across the coolant testing community.

The real time cavitation detection method, developed earlier by the author has been utilized for die purpose of quantifying cavitation intensity of various rigs and horns at various power settings. In addition, results have been correlated to vibrational displacement measurements across the surface of the testing coupons that has been performed at the Center for Manufacturing Research and Utilization at the Tennessee Technological University. The results and findings of current work have been reported to the ASTM D15.1 1 Subcommittee to help in establishing global standards for cavitation corrosion performance of coolant by ultrasonic testing methods.