Numerical prediction of the galling of aluminium alloys in cold strip drawing

A methodology based on finite element computations is proposed to predict the galling onset of aluminium alloys in cold forming. The methodology assumes that galling starts as soon as a finite element in the area of contact has reached a critical damage. The damage is calculated using Xue's model, which takes into account the effect of tangential stresses on the damage evolution. The tangential stress is calculated using Wilson's mixed lubrication model taking into account the roughness of the tools. Strip reduction tests were performed on aluminium AA6082 specimens, with and without lubricant. The proposed numerical model is in good agreement with experiments and is able to predict the onset of galling. The model is sufficiently accurate to determine the effect of tool roughness.