Machine tool construction calls for subassemblies with reduced weight while retaining excellent dynamic properties. Modern frame components do always meet required static stiffness but often display oscillation problems due to low component wall thicknesses. Breaking down solid steel structure into wide‐area sandwich designs such as steel‐aluminum foam‐steel panels results in good static properties to be combined with excellent properties since these sandwiches have 30 to 40 times the flexural strength. This is due to their major geometrical moment of inertia in relation to adequate‐mass steel sheet metals. In addition, the foam core dampens oscillations. Studies on foamed steel sections indicate that 2 to 3 times higher damping is likely in relation to unfoamed steel sections. These benefits were the motivation for the Chemnitz Metal Foam Center to accelerate development of extremely large‐format sandwiches with dimensions of 1,500 × 1,000 mm2.

Fast-moving machine tool assemblies should be light and rigid. Because of the lightweight construction and the dynamic loads these assemblies are very often susceptible to vibrations. Aluminum foam sandwiches are laminates with an aluminum foam core and compact cover sheets. The foam cores possess a high-energy absorption capacity. Machine tool assemblies made of aluminum foam sandwiches offer very high flexural stiffness, together with comparatively light weight. Vibrations generated by machining are damped very well due to the cellular structure of foam. The manufacturing process of foam sandwiches is in general well understood, but there are still some open questions concerning the mechanisms of bonding and adhesion between cover sheets and foam core. This paper tries to give answers to these questions

Sandwich structures consist of one light core layer and two top layers, which form the load-bearing structure. These layers have to be stiff and strong and have to protect the structure against indentations. The main task of the core layer is to keep the top layers in place and to generate a high shear stiffness. In order to obtain the required space between the top layers, the core layer has to have a high specific volume. Different sandwich materials with aluminium or steel top layers and cores of aluminium combs, corrugated aluminium sheets or aluminium foams are already known. In order to obtain better properties in terms of strength fibre-reinforced plastics (FRP) are utilised as top layers; this is the focus of numerous of the current research studies. The sole use of these materials leads to negative effects regarding the damage and impact behaviour. New top layers with high strength and high stiffness characteristics as well as good damage tolerances are to be expected by utilising metal layers in combination with endless fibre-reinforced plastics, so called hybrid laminates. These hybrid laminates combine the positive properties of metals (e.g. ductility) and fibre-reinforced plastics (e.g. tensile strength). The focus of this investigation lies on the production and characterisation of sandwich structures with aluminium foam core layers and hybrid laminate top layers. The foam cores consist of closed pore aluminium foams produced by utilising ingot and powder metallurgical techniques. The top layers consist of glass fibre-reinforced thermoplastics and aluminium layers. The production of the sandwich materials is realised by means of thermal pressing.

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