The Optimization of the Homogenization Treatment of AA7075

The homogenization treatment of 7075 aluminium alloy slabs is required for ensuring the technological properties for later processing. This usually has two stages. The soaking time in the second stage has an important influence. In order to evaluate the influence of this parameter, the homogenization, solution heat treatment, quenching and ageing treatment were simulated in the laboratory at various homogenization soaking time between 4 and 24 h. The evolution of the eutectic structures in the as-cast and homogenized 7075 aluminium alloy were investigated by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), differential scanning calorimetry (DSC) and tensile test. The results demonstrate that from many standpoints (mechanical properties, microstructure etc.) the complete dissolution of all soluble phases ends before the limit of 20 h that is considered as standard all over industry.