Solidification cracking susceptibility of quaternary aluminium alloys

The solidification cracking susceptibility was calculated for quaternary Al–Si–Mg–Cu, Al–Zn–Mg–Cu and Al–Li–Mg–Cu alloy systems. It was calculated based on the crack susceptibility index |dT/d(fs)1/2|, where T is temperature and fs the fraction solid. Three different levels of back diffusion were considered: no diffusion, diffusion under a cooling rate of 100 oC/s and diffusion under 20 oC/s. The calculated results were first validated by experimental data previously reported, and then extended to the composition ranges where no experimental data are available. For each alloy system, the crack susceptibility was calculated for 132651 Al alloys, with six crack susceptibility maps covering 15606 Al alloys at each diffusion level. These calculated results can be a database useful for welding, casting and additive manufacturing.