Composition and volume fraction changes in Ag-Al eutectic alloys

The system Ag-Al contains a eutectic between the aluminum solid solution and a compound Ag2Al, and the liquidus, solidus and solvus slopes on either side of the eutectic are very different. The coupled region has been determined for conditions of high temperature gradient and relatively low growth rates and it has been shown how the composition and volume proportions the phases change with freezing rate in a given alloy. In the solid state it is shown how some adjustment towards equilibrium proportions takes place in the as-frozen eutectic at high temperatures by uniform migration of the eutectic interfaces, and at lower temperatures by precipitation within eutectic lamellae. Volume fraction and composition changes in primary aluminum also occur by two mechanisms, one of which is possibly unique