ThinKing March - Functionally optimized lightweight materials - the InSeL Project develops porous metal foam material with high stiffness



Metallic foam structures offer promising application potential. Due to their structure, they are naturally lighter than solid forms. By combining these structures with other materials, custom formed materials can be developed whose properties and behavior are tailored to specific applications in areas ranging from the automotive industry to machine manufacturing, aeronautics, energy technology and biomedicine. These foam structures are the focus of the new German research project and cluster "Innovative Foam Structures for Efficient Lightweighting" (InSeL). The goal of this project is to develop functionally optimized lightweight materials using open-pored foams for industrial applications.

The Development Agency for Lightweighting Baden-Wuerttemberg is presenting this innovation as its ThinKing for March 2017. Leichtbau BW GmbH grants this distinction every month to innovative products and services from the Baden-Wuerttemberg lightweighting sector to promote new technological developments in the region. Using a holistic approach, researchers will use porous metal foams in the coming years to create independent cellular lightweight materials and composites with inherent skeletal supporting structures. At the same time, a new procedure is being developed which can create monodisperse polymer foams using surfactants. This procedure is intended to replace the manufacturing process using casting models to produce cellular lightweight structures and in combination with investment casting allow for the production of precise and reproducible foam structures.

Metal foam services serve functional purposes

With open pored metallic foams there are no separating walls between the individual cells. This allows for other substances to permeate the foam. It also allows the large surface area to be used for functional purposes. This means that the interesting mechanical properties of the metal foam can be combined with other properties.

The InSeL project is focused on defining and improving the property profiles of metallic foams. The project is divided into several subgroups in which some of the metallic supporting structures will be enhanced by other materials (such as ceramics) in a send stage in order to improve material strength or a non-metallic phase in which another material is infused into the foam (typically simply using air in open pored metal foams).

Huge application potential for the new materials

The metal foam allows for applications such as creating a matrix material with excellent insulation properties and with a web-like and highly stable supporting structure. "We use the open pore metallic foams as they are already known and modify them by developing new processes in order to create material combinations that have never existed before – particularly in view of lightweighting issues," says Prof. Norbert Jost from the Pforzheim University of Applied Sciences and the spokesman of the research cluster. "The potential and range of applications of these new materials appear almost endless."

Open pore metallic foams are suitable for combining their structure with a base material for a range of application areas, including vehicle bumpers and crash absorption as well as in the areas of heating/cooling technology and medical implants. Lightweight technology has a focus on achieving strength and stiffness without adding additional material if possible and on improving material efficiency and strength under different load profiles.

For such applications, open-pored metal forms have some very promising properties. Most notably, they have very high stiffness and strength. Under identical loads testing compression and bending, depending on the induced expansion up to 50 percent of the weight can be reduced in comparison to solid components. In addition, open pore metallic foams have excellent insulation properties.

Interested companies can get involved

The InSeL project as a ZAFH (see below) is subsidized with up to 1.5 million euros by the state of Baden-Wuerttemberg and structured funding from the European Union. The universities of applied sciences in Pforzheim, Karlsruhe and Reutlingen collaborate with the Karlsruhe Institute of Technology, the Natural and Medical Sciences Institute at the University of Tübingen and the Fraunhofer Institute of Chemical Technology in Pfinztal.

Plans have been made for the medium term implementation of the developed materials in specific industrial applications as well as the implementation of the developed monodisperse polymer foams as original form giving models for cellular metallic material composites. Interested companies that are interested in participating in the project are actively being sought.

In order to continue to develop the market potential and the manufacturing possibilities of the new materials for specific applications, several companies are already involved in the project including Indutherm Giesstechnologie GmbH in Walzbachtal, Tinnit GmbH and BTE GmbH in Karlsruhe as well as Mayser GmbH in Lindenberg and cirp GmbH in Heimsheim. The constant exchange between theory and practice is further promoted by the State Agency for Lightweighting Baden-Württemberg as well as the Northern Black Forest Chamber of Commerce and the Karlsruhe Chamer of Commerce.

A public InSeL symposium is planned following the initiation of the project with presentations from experts in the different work groups on select issues and applications. Press Release