No abstract

In the past it could be proven that aluminium foam is a construction material appropriate for numerous applications. The widespread use of aluminium is still hampered by the high production costs resulting on the one hand from the costly production method, and on the other one from expensive starting materials. The present work focuses on studies on alternative, cheaper starting materials. The results presented in this work support the idea that aluminium chips may be successfully used as base material instead of atomised powders. It could also be proven that good foaming rates can be achieved with calcium carbonate as foaming agent for aluminium

We have created a new architected material, which is both highly deformable and ultra‐resistant to dynamic point loads. The bio-inspired metallic cellular structure (with an internal grid of large ceramic segments) is non-cuttable by an angle grinder and a power drill, and it has only 15% steel density. Our architecture derives its extreme hardness from the local resonance between the embedded ceramics in a flexible cellular matrix and the attacking tool, which produces high-frequency vibrations at the interface. The incomplete consolidation of the ceramic grains during the manufacturing also promoted fragmentation of the ceramic spheres into micron-size particulate matter, which provided an abrasive interface with increasing resistance at higher loading rates. The contrast between the ceramic segments and cellular material was also effective against a waterjet cutter because the convex geometry of the ceramic spheres widened the waterjet and reduced its velocity by two orders of magnitude. Shifting the design paradigm from static resistance to dynamic interactions between the material phases and the applied load could inspire novel, metamorphic materials with pre-programmed mechanisms across different length scales.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

No abstract