DIE FILLING AND SOLIDIFICATION OF AL-SI ALLOY IN HIGH-PRESSURE DIE-CASTING

An industrially manufactured high-pressure cold chamber die-casting sp ecimen was examined metallographically to characterize the solidificat ion behaviour of the alloy, LM24, during casting. In addition, a serie s of controlled solidification tests were carried out on LM24 alloy an d it was shown that the local solidification time, t(f), and secondary dendrite arm spacing, SDAS, have the following relationship: (SDAS) = (9.21+/-1.05) (t(f))(0.341+/-0.016). The above-mentioned equation was then used to estimate the solidification time of the wad, runner and casting sections of the die cast specimen.