Liquid metal model experiments on casting and solidification processes

Abstract

This paper is concerned with laboratory studies using liquid metals with T _melt ≤ 300°C to model the flow of metals in industrial processes. Considering three selected examples the main features of such cold models are described. In the first instance we examine an aluminium alloy investment casting process. The requirement of reducing high flow velocities was achieved by the application of a static magnetic field. Local velocity measurements as well as integrated flow rate determination were carried out using eutectic InGaSn (T _melt = 10°C). Secondly, model experiments were performed on the electromagnetic stirring of liquid metals in a cylindrical cavity. We applied a rotating magnetic field (RMF) and a travelling magnetic field and recorded flow maps by means of ultrasonic Doppler velocimetry. With the goal of an efficient 3D-mixing, measurements were made using a combination of both field types with promising results. Thirdly, we report on systematic studies of the effect of an RMF on the solidification of a PbSn alloy. Directional solidification experiments demonstrate the influence of the electromagnetically driven convection on the resulting microstructure.