New capabilities in the numerical simulation of aluminium alloy casting processes

Abstract

A numerical procedure for the prediction of the mechanical performances of squeeze cast ingots of an aluminium alloy is presented. A 2D finite element (FE) model was used to simulate the ingot cooling under squeezing. Extracting the ingot cooling rate across the aluminium alloy freezing range, it was possible to predict the average microhardness by using a material equation which takes into account the dependence of the mechanical properties on the cooling rate. The model was experimentally calibrated by means of laboratory tests. Some cylindrical ingots were direct squeeze cast at different mould temperatures and squeezing pressures. The ingots were characterised by surface analysis, optical microscopy, instrumented macro-indentation and Vickers microhardness. The agreement between the experimental average microhardness and the predicted one was optimal for each ingot.