Cluster of Excellence - Integrated Material Systems IMS
In early 2009 a group of dedicated researchers from materials, chemical and electrical engineering joined their academic forces to apply for funds from the Landesexzellenzinitiative Hamburg - Hamburgs’ Cluster of Excellence. In July 2009 their inter-departmental and inter- institutional research project Integrated Materials Systems-IMS was among the eight projects chosen by the Behörde für Wissenschaft und Forschung, Hamburg (Department of Science and Research).
The development of microstructurally controlled, damage tolerant and lightweight materials with integrated sensing and actuating functions is the objective of this research project.
The scientific challenge is to explore the high potential of integrated materials systems by combining the degrees of freedom of microstructural design with lightweight and functional materials.
IMS is now based on a cooperation between the Hamburg University of Technology TUHH, GKSS Research Centre, Deutsches Elektronen-Synchrotron DESY and the University of Hamburg.
Areas of Application
Materials technology in Germany is the basis of a one-trillion-euro industry employing five million people. In the metropolitan region of Hamburg and its neighbouring North German states, major economic driving forces include the aircraft and automobile industries, wind power plants, medical technology and the Hamburg harbour, where lightweight structural parts are key components for future system development.
Scientific Back-ground and Project Plan
Properties of multiphase materials depend on the length scale, microstructural topology, and order of the compositional heterogeneity. Homogeneous systems have compositional heterogeneities on a subnanometer level, like in crystals or solutions. Increasing the length scale of compositional heterogeneities to the nanometer range, we have so-called microphase-separated structures, as found in block copolymers, vesicles or micellar solutions. At larger length scales, compositionally heterogeneous systems are macrophase-separated.
In this Cluster of Excellence we aim for multiphase systems on length scales from the micro- to macrophase-separated states, which combine the properties of the different components in a synergetic way.
IMS differ from other materials in that they combine excellent mechanical properties, such as strength or stiffness, with important functional properties, which allow in situ damage detection, strain monitoring or actuating. In comparison to manually made hybrid materials, which combine different materials on a macroscopic length scale, the envisioned IMS will combine (and keep!) the individual properties of the various phases on a much smaller length scale (below one millimetre). Such materials can be considered quasi-homogeneous materials from many practical points of view, as their properties will be size independent above approximately 1 mm.
For the synthesis of IMS, knowledge-based and novel high-throughput-methods (complex automatic parameter scans) are to be applied and established on a parallel basis.
Process and materials modelling combined with 3D x-ray tomography and high resolution X-ray scattering methods at DESY and the GKSS satellite station at DESY will support the identification of structural and functional microstructure-property-relationships on length scales ranging from the nanometer to the millimetre scale. By understanding of the physical and chemical mechanisms concepts for the development of IMS will be developed.
Challenges for the syntheses and function of integrated materials systems are manifold. Processing methods must be established which enable the control of the topology of e.g. interpenetrating networks or other regularly structured multiphase materials on different lengths scales with different materials. These controlled microstructures must be designed by knowledge-based modelling. Analysis methods are needed which allow a controlled feed back loop.
Since July 2009 scientist working in three Project Groups (A – C) are involved in the research:
Research Area A
Novel hierarchical ceramic/metal-polymer composites with extremely small amounts of polymers
This approach places emphasis on a hierarchical structure from the 50 nm scale up to the mm-scale. The novelty is that the polymer content should be kept very low, down to 1 vol% and act as the glue between the solid particles. The concept is mimicked from hard tissues such as enamel, which is very hard and stiff even though proteins and water interconnect it. It is expected that these tailored composite materials will lead to very hard (up to 5 GPa) and stiff (up to 100 GPa) IMS, which are nevertheless very damage tolerant. They can be produced at temperatures around 200-300 °C in short times. The production process offers a variety of possibilities to tailor the hierarchical structure, their polymer/ceramic and metal constituents and, as a result their functionality.
Research Area B
Hierarchically structured polymers and polymer composite materials
Fibre reinforced polymers are increasingly used for structural applications, due to their high specific properties. Without support from the matrix polymer, the fibres cannot be utilised to their full extent. However, a strong fibre is combined with a relatively weak matrix, which leads to a high anisotropy in properties and therefore to a specific composite-related design. In order to further improve the composite properties, nanoparticles (as fillers) can be added to the polymer matrix to further improve their behaviour. These nanocomposites will not only positively influence the properties of the neat polymer (strength, toughness, electrical and thermal properties, fire, smoke, and toxic behaviour, durability and fatigue resistance) but also, when used as matrix, that of the fibre composite. This is especially due to improvements in compressive behaviour, interlaminar shear, impact and delamination resistance. The composite will become a hierarchically structured material ranging from the nano to the metre level, or from the polymer to the fully assembled structure. Not only the mechanical properties will benefit from the nanofillers in the matrix, but also physical properties such as thermal and electrical conductivity can be enhanced. The later opens the possibility of new functionalities, such as structural health monitoring.
Research Area C
Self-assembled ceramic photonic crystal composites for high temperature control
High temperature conditions play a vital role in structural components such as in combustion engines, gas turbines and process industries. Temperatures may run up well beyond 1000°C generating significant thermal radiation and thus posing high demands on the stability of the components.
The key concept of this project is to create a novel material system by self assembly which hierarchically integrates the functionalities of a high temperature stability and mechanical strength with that of a photonic band gap to modify the thermal radiation towards a structural component at high temperatures. This concept has the potential of making a strong impact on various industries.
Coordinator and Speaker:
Prof. Dr. rer. nat. Gerold Schneider
Technische Universität Hamburg-Harburg
Institut für Keramische Hochleistungswerkstoffe
Tel.:0049 40 42878 3037