Cavitation analysis in aluminum alloys hot deformed by tensile test and creep in the as-cast and heat treated state

Hot deformation of some alloys can lead to cavitation (fissures) phenomenon. Cavitation is due to microstructural features and/or process parameter. The phenomenon is particularly critical because it limits the hot workability of materials, can cause premature fracture and serious problems on mechanical properties of finished products. The interest in understanding and controlling the microstructural and process factors that cause cavitation has led to this study. The paper analyzes the cavitation exhibited by two Al-Zn-Mg alloys deformed by both hot tensile test and creep at different temperatures (T) and strain rate (έ). The study has allowed of identify and justify the fundamental relationship between cavitation, microstructure and process parameters. Furthermore, the influence of different heat treatments (aging T6 and solutionizing) on cavitation has been evaluated. Microstructural and mechanical characterization of these alloys may also provide information for identifying their correct formability window