Fraunhofer Institute for Mechanics of Materials IWM
Fraunhofer Institute for Mechanics of Materials IWM

Using the virtual microscope to gain insight into materials.

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Multiscale Modeling and Tribosimulation

We perform numerical simulations on various scales into the static and dynamic properties of material systems in order to understand the relationship between the macroscopic material, component and process properties and the micro-structural mechanisms. This allows us to bridge the gap between quantum theory, atomistics, mesoscopy and continuum theories to make fundamental improvements to industrial material synthesis methods and process controls. Our findings are used to reduce friction and wear in tribological systems as well as in the knowledge-based design of nano-materials and suspensions. 

What we offer

 

  • Multiscale modeling of tribological systems with the aim of reducing friction and wear
  • Development of material structures under mechanical loads; shear-induced phase transformation; atomic scale wear; supralubrication
  • Molecule interactions with solid surfaces; interaction of solid surfaces; surface mechanochemistry; calculation of energy materials
  • Lubricants under extreme conditions; nanorheology; adsorption, diffusion and transport of additives; stability and dynamics of supramolecular structures

Topics

 

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Multiscale modeling

 

Continuum description of processes and materials requires reliable constitutive material equations to successfully predict material and component behavior. In the past, an empirical formulation of these constitutive laws was usually the only possibility. Now, however, they can be reduced to their basic mechanisms through mesoscopic, atomistic, and quantum mechanical modeling and significantly improved. Scale coupling allows for a seamless description of material systems ...

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Nanotribology 


The complexity of friction phenomena results from their being inherently multiscale. The computer aided design of tribocontacts is therefore able to handle all scales of the atomistic description of the contact up to the elasto-hydrodynamics of the lubrication gap. Quantum chemical calculations describe possible reactions between basic lubricants, additives, oxygen and the involved surface. Molecular dynamic simulations provide the boundary conditions for continuum-mechanical lubricant ...

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Layer growth processes


The optimum design of coating processes is still complicated by the need for a large number of preliminary tests. The simulation helps here to drastically reduce the process window, identifying the relevant microscopic mechanisms that lead to a desired microstructure or topography.

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Particle simulation

 

Particle-based simulation methods are used and further developed to simulate the manufacturing processes with particle materials, liquids or suspensions. The discrete element method (DEM) describes the morphology, interaction and dynamics of individual grains. When combined with dissipative particle dynamics (DPD), it is well suited for the simulation of suspensions, such as those used as an abrasive in silicon wafer wire-sawing. Fluids with complex rheology can be described with the aid ...

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Nanomaterials

 

Scale approaches are often used in the miniaturization of components, i.e. one assumes that the physics that exist in large systems also hold true on a small scale. However, if the dimensions of a component or a material’s structural unit exceed a certain intrinsic size (for example, the de-Broglie wavelength of conduction electrons), the material can exhibit completely new properties. The hopes frequently placed in nanotechnology are reliant on the possibility of controlling these properties through ...

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Nanocatalysts


The search for optimal catalytic systems benefits from a fundamental understanding of the energetics and steric effects of the desired chemical reactions. Detailed calculations of heterogeneous catalysts can be carried out using density functional theory. Catalysts from supported nanoclusters are particularly interesting in this respect, because they often have higher catalytic activity than the corresponding systems with larger active centers...

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Nano- and microfluidics

 

The flow of small quantities of liquids in containers, as well as with free surfaces, can be simulated very realistically using molecular dynamics and smoothed particle hydrodynamics. Beneficiaries of these calculations include designers of nano - and microfluidic components, such as capillary pumps, injection nozzles and fluid switches. Tribology also benefits from a better understanding of lubrication dynamics in narrow crevices...

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Li-Ion batteries


Modern battery technology increasingly relies on nano-structured materials for cathodes and anodes. Using atomistic methods, it is possible to represent the transport processes to the surface, the intercalation of lithium in the materials, and any chemical degeneration mechanisms of the electrolytes on the electrodes. This supports the process understanding, which in turn can be used to optimise the materials involved...

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Carbon nanotubes

 

As described in the quote from Nobel laureate Richard E. Smalley, the outstanding electrical and mechanical properties of carbon nanotubes (CNT) offer a very promising future for applications in electronics, as well as being candidates for the targeted improvement of material properties of hybrid CNT systems. Simulation methods from density functional theory to molecular dynamics deliver important results about the intrinsic properties of CNT. But above all they lead to an understanding ...

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Multiscale Modeling and Tribosimulation publications

 

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Contributions to scientific journals, books and conferences as well as dissertations and project reports...

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Teaching

 

Prof. Dr. Michael Moseler, University of Freiburg

  • Winter term 2018/19: Computational Materials Engineering
  • Winter term 2017/18: Computational Materials Engineering
  • Summer term 2017: Computational Physics: Materials Science
  • Winter term 2016/17: Computational Materials Engineering
  • Summer term 2016: Density functional theory
  • Winter term 2015/16: Computational Material Physics
  • Summer term 2015: Computational Material Physics I: DFT
  • Winter term 2013/2014: Electronic structure of matter
  • Summer term 2012: Electronic structure of matter
  • Winter term 2011/2012: Computational Materials Science
  • Winter term 2010/2011: Computational Materials Science
  • Summer term 2010: Elektronische Struktur der Materie
  • Winter term 2009/2010: Theorie der atomaren Cluster: Konzepte und computer-gestützte Modellierung
  • Summer term 2009: Computergestützte Materialphysik II: Multiskalensimulation
  • Winter term 2008/2009: Computergestützte Materialphysik I: Dichtefunktionaltheorie
  • Winter term 2007/2008: Introduction to the theory of atomic clusters: concepts and computations
  • Summer term 2007: Einführung in die Multiskalenmaterialmodellierung
  • Winter term 2006/2007: Introduction to density functional theory
  • Summer term 2006: Surcafe growth: from toy models via continuum growth equations to fractal theories
  • Winter term 2005/2006: Introduction to Multiscale Modelling of Materials
  • Summer term 2005: Clusters on the computer
  • Winter term 2004/2005: Computergestützte Materialphysik
  • Summer term 2004: Fortran 90: Eine Einführung mit physikalischen Beispielen
  • Winter term 2003/2004: Dichtefunktionaltheorie: eine Einführung mit Computerexperimenten
  • Summer term 2003: Computergestützte Materialphysik

 

Sommer Schools, Prof. Dr. Michael Moseler

  • M.Moseler, Quantum Molecular Dynamic Insights into Tribochemistry, Summer School Tribology Today, Marrakech 8.4.-14.4.2018
  • M. Moseler, Sequential atomistic/continuum multiscale coupling, GAMM Multiscale Materials Modeling Summer School, Bad Herrenalb, 02. - 07.09.2012
  • M. Moseler, Serial Multiscale coupling schemes, COST Summerschool on multiscale materials modelling, Lappeenranta, Finland. 12. - 16.06.2007
  • M. Moseler, Multiscale Modelling of Nanomaterials, 15th Jyväskylä Summerschool,
    18. - 26.08.2005

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