Currently absent

Research Associate / PhD position in the field of computational atomistic modelling of materials

The research topic will be a fundamental investigation of structural and mechanical properties of interfaces in carbon/metal-carbide multilayer coatings on steel surfaces by means of atomistic simulations based on tight-binding models and bond-order potentials, which are constructed by means of first-principles density-functional- theory methods. The research goal will be to strengthen the theoretical understanding of cohesion, adhesion and mechanical response of multilayers of amorphous and crystalline phases at the atomic level, which will further support the technological development of better protective surface coatings for steel-based industrial heavy- duty components like drills or tubes under harsh conditions.

Research Associate / PhD position in the field of computational first-principles modelling of materials

The research topic will be a fundamental investigation of the transport and the segregation of metallic impurities at dislocations in Silicon by means of atomistic first-principles simulations based on density functional theory (DFT). Unlike highly pure single-crystalline Silicon, which is used mainly in microelectronics, so-called metallurgical Silicon is an inexpensive material and therefore economically attractive for mass production of solar cells. However, metallic impurities contained therein affect its electronic and optical properties strongly. Hence this material is only applicable even for simple solar cells if the impurities can be passivated inside the material’s microstructure. A particularly relevant issue is the segregation metallic impurities at precipitates or dislocations. Dislocations which are mobile at elevated temperature, offer a mechanism for “cleaning” a volume fraction of the silicon from the impurities. Hence, understanding the mobility of impurities and their segregation to dislocations from first principles is of high technological interest.

Modelling and Simulation: A continuum theory of dislocation dynamics

Predictive modelling of deformation processes is still a challenge in computational materials science. Within the newly established DFG research group FOR1650 - Dislocation based Plasticity - we develop a novel dislocation density-based continuum theory of plasticity. Starting from a discrete description of the dislocation microstructure we proceed towards a Continuum Dislocation Dynamics (CDD) theory. The open positions cover discrete dislocation structures and dynamics as well as their representation in the continuum framework.

The first position is concerned with the modelling of discrete dislocations (DDD). DDD is a powerful tool to follow plastic deformation via the motion of elementary materials defects. It  can serve as an essential guide for the development of the continuous CDD theory, since it gives complete control over the initial dislocation microstructure and complete information regarding its evolution. The tasks for this position are to improve large scale simulations of the motion of dislocations in well defined studies and the improvement of the computational efficiency.

The second position is concerned with the development and application of the CDD field theory. This requires conceptual/theoretical work as well as on the numerical implementation. Analysis of DDD data (see above) will give guidance towards identifying terms for short-range and long-range dislocation interaction. CDD may later be coupled to a crystal plasticity finite element framework, which will give access to the simulation of components and micro devices.

Altogether, the research group involves in total 6 closely interlinked projects covering numerical, mechanical and experimental aspects of micro plasticity.


Computational Materials Science

Die thematische Ausrichtung der zu besetzenden Stelle liegt im Bereich ,,Computational Materials Science‘‘. Es sollen Modellierungsmethoden zur Beschreibung der Phasenumwandlungen und Mikrostrukturausbildungen in Materialsystemen unter dem Einfluss verschiedener physikalischer Felder (z.B. Strömung, elektrische Spannung, Elastizität, Plastizität, Magnetismus) entwickelt werden. Der Einsatz schneller und paralleler Algorithmen auf Hochleistungsrechnern ermöglicht eine rechnergestützte Analyse von Prozessen in der Herstellung von Materialien und in der Fertigung von Bauteilen. Bei der Anwendung der Simulationsverfahren liegt der Schwerpunkt bei Prozessen und Materialien in Energiesystemen.
Bei Interesse wenden Sie sich bitte an Prof. Britta Nestler.

There are several experimental dectoral theses concerning reliability and safety of materials and component in microsystems technology and nano technology offered by the Institute of Applied Materilas - Material and Bio Mechanics at Campus Nord.

Please address your inquiries and applications to Prof. Dr. O. Kraft.