Simulation Experiments in Water for Ultrasonic Detection of Inclusions in Molten Metals

In lightweight metal processing, the metal cleanliness is a crucial process parameter for part manufacturing and recycling. On-line ultrasonic methods to evaluate the cleanliness of molten metals by counting the number and measuring the size of inclusions in molten metals are highly desired. In this study, a particle flow simulation system using water has been constructed in order to establish the procedure and to investigate the optimum system configurations for cleanliness evaluation of molten metals. Counting the number and measuring the size distribution of the polyvinyl chloride (PVC) particles, having a mean diameter of 128μm, suspended in water with the PVC volume concentrations of 5ppm and 10ppm were performed with ultrasonic pitch-catch configuration at a frequency of 10MHz. The ultrasonic signals scattered by the particle were detected and the particle movements were observed. It was verified that the particle movement in the ultrasonic sensing area in water was successfully controlled by the water pump and tube used in the system. The counted numbers of the particles by the presented method and system had good agreement with the calculated results with a count error of less than 10% or two counts.