Energy absorption capability of graded and non-graded sheet-based gyroid structures fabricated by microcast processing
Leonie Wallat, Michael Selzer, Uwe Wasmuth, Frank Poehler, Britta Nestler
Abstract
This review analyses the design, manufacture and mechanical behaviour of sheet-based gyroid structures with different gradients, made of the alloy AlSi7Mg0.6. Contrary to most contributions, additive manufacturing was not used for the production of the metallic lattices. The lattices were manufactured by microcast processing, which represents an alternative manufacturing option for complex structures. Five different gyroid structures of AlSi7Mg0.6, with a porosity between 40% and 80% and different gradients, are produced and analysed. The special feature here is that, in addition to constant and linear gradients, a non-linear gradient is also taken into account. With the introduction of a non-linear gradient, a hardly considered structure is introduced. By introducing new gradients, the structures can be better adapted to their environment. The main focus of the mechanical behaviour analysis was on the possible energy absorption capacity. For this purpose, compression tests were performed. The plateau of the resulting stress–strain diagram of structures with constant porosities of 80% and 60% characterises an ideal course for energy absorption. However, graded porosity structures with porosities ranging from 80% to 40% have a higher energy absorption capacity than the structures with a constant porosity of 80%. The results show a new possibility that a targeted adjustment of the energy absorption potential is possible through future topology optimisation, which would be attractive in industries with crash safety areas.