Sammendrag
The permeability in the mushy zone during the solidification of shape castings affects many characteristics including porosity, which is the most important defect that deteriorates the mechanical properties. Measuring the permeability in a solidifying alloy is, however, challenging due to several simultaneously acting phenomena such as heat transfer, macrosegregation, and melt flow. In the present study, a new experimental permeability device (“permeameter”) is presented and used for measuring the permeability in an A356 aluminium alloy. The liquid flow rate in the device is measured and related to the permeability through the Darcy’s law. A series of experiments have been carried out at 571°C, 572°C, and 573°C, and the reproducibility of the “permeameter” has been assessed. The results, furthermore, indicate that the presented experimental device is a useful tool for quantification of porosity and can be applied to different alloys and casting conditions.