Liquid Metal Flow Studied by Positron Emission Tracking

To improve the properties of castings, a new technique to observe the fluid flow and study the motion of oxygen-bearing inclusions has been developed. This new technique, Positron Emission Particle Tracking (PEPT), enabled a single radioactive tracer particle, moving inside a liquid metal casting, to be tracked with an accuracy of some millimeters, depending on the properties of the liquid metal and the mold. These novel experiments give promising results to observe the liquid metal flow and locate the tracked particle in a casting. Experiments have shown that various particle sizes (200 to 600 mu m presented here) can be used to observe the liquid metal flow, if the particle has sufficiently initial radioactivity. Different sizes of particles are considered and their radioactivity compared in terms of their usefulness for tracking in flowing liquid aluminum according to the specific surface area.