Abstract

Cavitation Intensity Measurements in Melts

V.Lanin (University of Informatics and Electronics, Minsk, Belarus )

e-mail: lanin@bsuir.unibel.by

The greatest spectral density of a cavitation noise is in the band from 20-th up to 40-th harmonics of the base frequency as 22 kHz . It is offered to measure the square of spectral density of a cavitation noise and judge the value of cavitation pressure in melts. The cavitometr consists of a piezoelectric sensor, an active filter, a square-law detector, a recording device and measures cavitation pressure from 5 up to 50 kPa in the band 18 - 60 kHz with accuracy 10 %. The greatest value of cavitation pressure in solder melts makes 3 - 3,2 kPa and is observed at frequencies superior to resonant one by 0,2 - 0,5 kHz. The value of cavitation pressure in solder melts does not linearly depend on the angle of entering oscillations and gap between butt end and measuring probe. The greatest value of cavitation pressure is observed when the gap is reduced up to 0,1 mm and the angle is close to zero point for longitudinal oscillations. Parallel oscillations obtain consid! erable cavitation pressure in melts at gaps 0,15 - 0,3 mm and angles 0 - 15 grad. It increases productivity of processes of US soldering and metallization.

Section : 4