The analysis of changes in forces caused by solid probe passage through interface between two fluid phases
Jacek Jackowski, Magdalena Suchora-Kozakiewicz
Quarterly No. 2, 2013 pages 107-112
DOI:
keywords: interfacial tension, methods, measurement
abstract A significant role in metallurgical and foundry processes, inclusive of the ones related to composite material technology, is played by interfacial tension arising in technological systems. In the systems related to the technology of composite castings (both ones reinforced with particles and with saturated reinforcement), interfacial tension, particularly during recycling processes, appears at the boundaries of three phases: liquid metal (alloy), liquid slag, and atmosphere, in any combinations. Knowledge of the values of these parameters facilitates the designing of technological processes. Therefore, a useful measurement method of these tensions should allow for the measurements to be carried out during a single experiment. The authors have tested a chosen method, being a combination of plate and ring methods, and found its usefulness in the case of systems composed of liquid aluminum alloys and melted salt mixtures. Since the method is based on the measurement and recording of the forces acting at the probe (solid phase) moving successively through a layer of liquid metal (alloy) to the layer of liquid slag and, afterwards, to the atmosphere, proper interpretation of the plots of the changes in the forces recorded by the measurement system have become very important. Observation of the measurement process in real systems is very difficult (or even impossible). Hence, the authors have carried out tests with the use of equivalent media at room temperature, and obtained model plots of the recorded changes in the force values in conditions of fully clear behaviour of the examined systems. Thanks to these experiments and the observations, the authors have attained necessary and unquestionable information for full interpretation of plots illustrating the changes of recorded forces under the conditions of tests using metallurgical systems occurring in the technology of e.g. recycling of cast composite materials in the matrix of aluminum alloys.