Metallurgical and material properties correlations between machined and severely plastic deformed aluminium alloy

The possibility to study and clearly define the physics phenomena that occur during the machining process of various metal materials is becoming one of the interpretative keys to quantify a product's quality and life cycle performance. An accurate understanding of the surface integrity can be achieved through the knowledge of the fundamental details about the mechanical response and the behaviour of the affected material layers caused by thermo-mechanical loads induced by machining operations. Therefore, this set of information can help the designer to produce parts with superior quality. The aim of this work is to study the surface layer states in terms of metallurgical and mechanical properties of aluminium alloy 7075 in a machined and a sereverely plastic deformed by the Equal Channel Angular Pressing (ECAP) process. The outcomes provided by the experimental measurements permitted to find possible links regarding the microstructural and hardness changes observed between the machined surface layer and the region of material deformed by ECAP. Finally, this scientific investigation aims to establish the basis for an innovative method to study and quantify the metallurgical phenomena that occur beneath the machined surface of bulk metal materials.