Cryogenic forming of AA7075 by Equal-Channel Angular Pressing

As high strength aluminum alloys are generally hard to deform, the application of conventional severe plastic deformation methods, which in principle allow the generation of ultra fine grained microstructures and increasing strength, is limited. In this study, cryogenic ECAP deformation as an alternative approach to deform a 7075 alloy is explored. Here, a tool with an internal angle of 90 degrees is used. We demonstrate that cryogenic ECAP (followed by suitable heat treatments) results in increases of the degree of deformation, strength and ductility. Moreover, we present first results on the effect of cryogenic ECAP on microstructural evolution and mechanical properties of the 7075 alloy that demonstrate the potential of cryogenic forming to produce improved properties of high-strength aluminum alloys.