Assessing the performance of rolled vs machined Isogrid structures: microstructural characterisation and mechanical properties

Isogrid is a lattice reinforced sheet structure with a proven track-record for improving the mass efficiency of sheet metal components. The isotropic and mass efficient mechanical properties of Isogrid suit a wide range of applications from the aerospace sector to construction. While replacing flat sheet metal with Isogrid has a high potential impact for the reduction of metal usage globally, current production methods (primarily CNC milling of thick plate) are not viable at mass manufacturing scale. Consequently, a novel method has been proposed to enable high volume production of Isogrid via rolling. However, rolling structures with non-constant or periodic cross sections is unorthodox, and the potential effects on the mechanical properties of Isogrid remains unknown. Herein, it is shown that rolling AA1050 into an Isogrid form improves its bending strength by 20% and tensile strength by 15% compared to machining for the same geometry with a more isotropic distribution of mechanical properties. These results demonstrate that rolling is a viable method for Isogrid production at scale and may enable greater resource efficiency in the domain of sheet metal manufacturing and construction.