CAVITATION EROSION TEST METHOD Russian patent published in 2020 - IPC G01N3/56 G01N3/32 

FIELD: physics.

SUBSTANCE: invention relates to control of resistance (strength) of materials and their protective coatings under action of concentrated flows of substance and energy. Essence: placing a sample with a test material in a liquid medium in front of the end surface of the emitter of ultrasonic oscillations, providing oscillations at the ultrasonic frequency, cavitation process is formed in the gap between the end surface of the radiator and the sample and is implemented for a time sufficient for destroying the surface of the analyzed material, and cavitation resistance is determined by change of thickness of analyzed material. Ultrasonic vibrations are introduced into the liquid medium through a radiator which is multiple along the length of half the wavelength and made of a thermo- or chemically resistant material. A portion of the working tool, which is a multiple of the length of a quarter of the wavelength, is placed in a medium with abnormal conditions of chemical activity, temperature or pressure, and another multiple quarter-wave length of part of tool on side of connection with piezoelectric transducer is placed under normal conditions and provides its cooling. Amplitude of vibrations of end surface of working tool in liquid medium with abnormal conditions is set by current value of mechanical branch of piezoelectric transducer. In the course of the cavitation process implementation, the cavitation medium cavity resistance change rate is continuously monitored based on the measured values of the mechanical branch and voltage current on the piezoelectric transducer and its value is compared with the value of the rate of change of wave resistance of water under normal conditions and their equality is established by moving the sample with the test material in the direction to the end surface of the radiator. Minimum power supply voltage value is set sufficient to provide preset speed of wave resistance variation at minimum amplitude of oscillations.

EFFECT: higher reliability of research results and enabling correct decisions when selecting materials for operation under cavitation conditions in conditions which are abnormal by temperature, pressure and degree of aggressiveness.

1 cl, 5 dwg