Design and development of megasonic system and its application to PZT nano powder dispersion

Although ultrasonic cavitation provides various applications for ultrasound, its inherent disadvantages can not be neglected. In ultrasonic dispersion process, ultrasound, in a frequency of 20 to 80 kHz, causes damages to materials due to excessive cavitation and inferior self-guidance. In order to alleviate cavitation and help the acoustic field focus, a novel megasonic implementing system has been designed and developed. It consists of a megasonic transducer and a Mega-Hertz power supply. The transducer is constructed in the form of cylindrical tube with a round piece of PZT-8 piezoelectric ceramic. The power supply provides sinusoidal voltage and current outputs at oscillating frequency ranging from 630 kHz to 650 kHz. The transducer consumes an electrical power of over 400W. The acoustic pressure is measured within the range of 2.86 MPa to 8.92 MPa by a PVDF sensor. Experimental results of Megasonic dispersion of PZT nano powder manifest the conglomeration prevention effect, which is characterized by Thermal Field Emission SEM (TFE-SEM), Transmission Electron Microscopy (TEM), and the stable constitution of PZT nano particle through treatment, which is confirmed by X-Ray Diffraction (XRD).