Effect of Fe Content on Hot Tearing of High-Strength Al-Mg-Si Alloy

The effect of Fe content on hot tearing of the high-strength Al-Mg-Si alloy was systematically investigated. In this study, a thermodynamic calculation software Thermo-Calc was used to calculate the solidification path under the non-equilibrium condition, and the mechanical properties of this alloy have also been investigated during solidification using an electromagnetic induction heating tensile machine. In order to confirm the calculation results of solidification path, a quenching test also was carried out. By using the Thermo-Calc, the sequence of crystallization, crystallization temperature of formed phases and their crystallized amount were systematically investigated for each alloy in which Fe content was changed. Furthermore, by comparing the fracture surfaces of the tensile testing sample and DC billet, the temperature range of crack initiation of the alloy was examined. Comparing the temperature range of crack initiation with the crystallization phase and its crystallization order, Fe content of high-strength Al-Mg-Si alloy influenced hot tearing significantly owing to the crystallization behavior of α(AlFeMn).