Theoretical and experimental study of liquid infiltration propelled by electromagnetic pressure

Abstract

We demonstrate how the axial component of electromagnetic pressure, which is generated by the impulse current in solenoid coils, can propel infiltration of microchannels using molten metals. The generated electromagnetic pressure was theoretically studied, and the results were compared with the critical pressure calculated using the capillary law. Then, the minimum current required to initiate infiltration when metals could not wet the template was determined. A self-designed electromagnetic infiltration apparatus was employed to study the experimental phenomenon. Experiments were conducted with calculated minimum current or low values by means of infiltration. The obtained microstructural images clearly revealed the full infiltration of microchannels when currents were equal to minimum values. However, when the current was lower than the critical value, electromagnetic pressure was insufficient to overcome capillary resistance in marginal areas. The insufficiency was primarily due to the radial decrease in electromagnetic pressure. When currents were further decreased, the proportion of fully infiltrated areas reduced gradually to zero, which was in good agreement with calculations. This study may represent the effective application of electromagnetic pressure in microchannel infiltration and the regulation of infiltration effects by adjusting current values. Methodologies and conclusions may also be used as guides in the future design and fabrication of composites using the electromagnetic method.