Reducing welding hot cracking of high-strength novel Al-Mg-Zn-Cu alloys based on the prediction of the T-shaped device

The higher hot cracking tendency during fusion welding in traditional high-strength 7000 series alloys has been an obstacle for its further application. In this study, the cracking susceptibility can be suppressed by fabricating Al-Mg-Zn-Cu alloys with Zn/Mg <= 1 and Cu/Mg <= 0.25 while simultaneously maintaining the high strength. A T-shaped device combined with non-equilibrium solidification is developed to simulate the solidification during fusion welding, and it is effective to predict the shrinkage load, temperature and solid fraction. The effect of solidification temperature range, the amount of eutectics at the terminal stage of solidification and the shrinkage load during solidification on the hot cracking susceptibility are discussed in detail.