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Modelling of atomic structures in nano-layers using the finite element method

 
: Neugebauer, Reimund; Wertheim, R.; Semmler, U.

:
Volltext urn:nbn:de:0011-n-1416582 (223 KByte PDF)
MD5 Fingerprint: f8d8daf3646ab8b731728eb87e286c2f
Erstellt am: 1.4.2011


Neugebauer, Reimund ; Fraunhofer-Institut für Werkzeugmaschinen und Umformtechnik -IWU-, Chemnitz:
Sustainable production for resource efficiency and ecomobility : Manufacturing Colloquium, September 29-30, 2010 Chemnitz; ICMC 2010
Zwickau: Verlag Wissenschaftliche Scripten, 2010 (Berichte aus dem IWU 54)
ISBN: 978-3-942267-04-5
S.855-862
International Chemnitz Manufacturing Colloquium <2010, Chemnitz>
Englisch
Konferenzbeitrag, Elektronische Publikation
Fraunhofer IWU ()
finite element method; nanotechnology; coating; nanoindentation

Abstract
Cutting tools for high performance cutting (HPC) processes or for hard-to-cut materials are unthinkable without coatings. For the development of new coatings and for the improvement of known tool coatings the knowledge of the properties of these layers has an immense significance. The behaviour of the coatings under thermal and mechanical loads can be examined by means of numerical simulation, e.g. using the Finite Element Method (FEM). Thick coatings (measured in microns to millimetres) can be modelled with continuummechanical material properties. However, for layers with decreasing layer thickness, the inhomogeneous and anisotropic crystal lattice structures and different material data in the grain boundaries and transition areas play bigger and bigger role. An increasing importance shows the so-called super-lattice coatings with hundreds of layers each of them having only few nanometres of thickness. Homogeneity or average material properties based on the properties of single layers are not valid in these dimensions any more. Consequently, continuum-mechanical material models cannot be used for modelling the behaviour of nano-layers. Therefore, the interaction potentials between the single atoms must be considered. A new, so-called Atomic FEM (AFEM) is presented. In the AFEM the inter-atomic bonds are modelled as non-linear spring-and-damper elements. The AFEM is the connection between the molecular dynamics (MD [1]) method and the so-called Crystal Plasticity FEM (CPFEM [2]). The MD simulates the atomic deposition process. The CPFEM considers the behaviour of anisotropic crystals using the continuum-mechanical FEM. The new method can be used to validate in the current Poster 855 investigations the nano-indenter test results [3]. Using the CPFEM results by means of AFEM the deformation, the crack and dislocation behaviour can be simulated and calculated in the nanometer scale. The presented work is a part of the EU research project "Multiscale Modelling for Multilayered Surface Systems (M3-2S)".

: http://publica.fraunhofer.de/dokumente/N-141658.html