Deformation of AA6016 Aluminum Alloy Sheets at High Temperature and Strain Rate

The production of aluminum alloy components through sheet forming processes conducted at elevated temperatures is gaining more and more interest as it gives raise to the possibility of a significant enhancement of the metal formability characteristics, compared to room temperature forming. However, conventional forming processes at elevated temperatures on aluminum alloy sheets are usually carried out under superplastic forming regime conditions, which are too slow to be applicable to mass production typical of the automotive industry. The aim of the present study is to investigate the formability characteristics of AA6016 aluminum alloy sheets when deformed at elevated temperature, but in a range of strain rates higher than those usually applicable in superplastic forming. To this aim, uni-axial tensile tests were carried out to evaluate both the material ductility in terms of true strain at fracture as a function of the temperature and strain rate, and the alloy post-forming characteristics after testing. In such a way, the optimal forming conditions in terms of temperature, strain rate and microstructural features were identified.