Cavitation Erosion Test

The samples are immersed in a liquid. The test method generates cavitation erosion by vibrations on the surface of the samples. The amplified longitudinal ultrasonic vibrations generated by this device are causing pressure variations as ultrasonic waves in the liquid. The test bench is built according to the most important international standard. 

Applications

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Cavitation Erosion Test Bench – ASTM G32

description in picture of cavitation
Cavitation Erosion Test in progress

Standard:  ASTM G32

Frequence:  20 kHz

Amplitude:  50 µm

Results:  Weight loss

Note:  The given parameters are according to ASTM Standard. Others on request.

Principle

Cavitation, as a physical phenomenon, involves the formation and collapse of gas or vapour bubbles in a liquid. When the pressure in a liquid drops below the steam pressure, a bubble is formed. Then, when the pressure increases again, the bubble will implode, resulting in the formation of a liquid micro-jet of the collapsing bubble at the surface. If the bubble is near a surface, then this liquid jet acts like a water jet hitting the surface. Combined with the typical shock wave during collapse, both mechanisms can cause cavitation erosion damage to the surfaces of the materials. The cumulative pressurisation from the collapsing bubbles has been estimated in the literature to be on the order of 900 MPa, which can lead to local strain hardening and fatigue fracture in a ductile material or to crack propagation in brittle materials.

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