Prediction method of crack sensitivity during DC casting of Al-Mn and Al-Mg alloys

Because it has been difficult to predict crack sensitivity depending on alloy composition during aluminum direct chill casting (DC casting), a new prediction method based on the relationship between the calculated solid fraction and temperature was developed for Al-Mn and Al-Mg series aluminum alloys. In this work, two crack indexes are suggested. The first index is brittle temperature range (BTR). The second index is based on the strain rate difference in the mushy region. These indexes are quantitatively calculated by using thermodynamic software such as Thermo-calc. This method is verified by DC casting of A3000 and A5000 series aluminum alloys. It can be utilized in the alloy design stages to control the crack sensitivity before casting.