BIFILMS AND HOT TEARING OF Al-Si ALLOYS

Abstract

Hot tearing is one of the most interesting defects that can be found during casting of aluminium alloys. The definition of this defects has some uncertainties such as “it does not always appear under apparently identical conditions” or “the defect is highly specific to certain alloys”. There are several works in the literature on the modelling and analytical approaches. However, the experimental findings have not been satisfactory. In this work, A356, A380 and A413 alloys were cast in two different moulds to investigate the hot tearing tendency with regard to the melt quality. It was found that bifilms had dominant effect over the hot tearing.