Measurements and modelling of air gap formation in aluminium based alloys

Abstract

The formation of an air gap has been experimentally studied during solidification of several aluminium based alloys. Air gap widths and temperature distribution have been measured during solidification in a cylindrical mould. The effect of grain refinement on heat transfer and air gap formation has been studied. Mathematical modelling has been performed to increase the understanding of the solidification process and air gap formation. A model was developed for description of air gap formation in alloys solidifying with varying solidification intervals. The model includes the effect of formation and condensation of lattice defects on the solidification process and air gap formation. The calculated shrinkage using this model shows good agreement with the experimental data.