On-Line Monitoring of Liquid Metal Quality by Focused Ultrasound

点击翻译按钮获取中文摘要

A high performance ultrasonic sensor that provides a high spatial resolution measurement in high temperature environments has been developed in order to make an on-line monitoring of molten metal quality. Several experiments have been carried out using the developed focused sensors at 10 MHz in a pulse echo mode to investigate the performance of the developed monitoring system. Molten zinc, aluminum, and magnesium were used in the experiments. The main results obtained are the following:(1) It has been shown that a numerical simulation technique with a finite difference method is a very useful tool for better designing high performance ultrasonic sensors with a clad buffer rod. Using such simulation, focused ultrasonic sensors having excellent wave guidance ability with high signal to noise ratio have been successfully developed.(2) Laboratory validation of the use of focused ultrasonic sensors for inclusion particle detection in molten aluminum at 800 ℃ as well as molten zinc at 650 ℃ has been demonstrated. Back-scattered signals from particles in both molten metals are clearly visible at the focal region of the lens.It is therefore considered that the developed ultrasonic technique is a promising candidate for on-line monitoring during molten metal processing.