Aluminum foil erosion

Aluminum foil erosion Electrochemical method Polymer degradation... 

Known measuring techniques comprise local physical methods (hydrophones, thermoacoustic sensors, aluminum foil erosion, optical sound pressure and velocity sensors, radiation pressure scale, laser-Doppler anemometry), local chemical methods (Weissler reaction, chemiluminescence, electrochemical sensors), global chemical methods (model reactions), and sonoluminiscence (single-bubble sonoluminescence SBSL, multibubble sonoluminescence MBSL). 

Erosion of aluminum specimen and measurements with hydrophones show that there is a strong correlation between the zones with high absorption coefficients and zones of high cavitational energy. Indentations on aluminum foils can be seen primarily in these distinct areas with proper sound pressure, high sound... 

The erosion of pieces of other metals have been studied [120]. In some cases the amount of material removed is extremely small (e.g. 400 mg/h with lead). The better types of indicators are foils composed of aluminum or lead placed under slight tension. A further advantage is that the cavitation pattern is printed on the foil and in this way standing waves can be detected. 

Figure 10. Appearance of a titanium foil of 100 pm in thickness (a) with cavitation erosion and a form of cavitation failure (b, x300) after 15-min period of ultrasonic treatment in the developed cavitation mode in an aluminum melt.

Usually, holding a foil (for example, from Ti) in an aluminum melt without ultrasonic action for up to 1 h does not result in its wetting and subsequent metallization. Under ultrasonic treatment, a strong diffusive layer forms at the foil surface after 1-3 min of exposure, and typical punctures—traces of cavitation erosion—appear on the foil after 5—15 min (Figure 10). 

---