Numerische Mikrostrukturoptimierung schmelzinfiltrierter Metall-Keramik-Verbundwerkstoffe
Materialien und Werkstoffe der Sinterprozesse und der generativen Fertigungsverfahren
Zusammenfassung der Projektergebnisse
Melt-infiltrated metal/ceramic composites with lamellar microstructure are materials in the development stage and show strong dependence on their macroscopic thermomechanical properties due to the orientation distribution of the lamellar domains. The creation of a virtual model of their microstructure and, consequently, their application for performing microstructural optimization will support the well-directed production of these materials. The microstructure modeling and numerical optimization make it possible to describe numerically the behavior of the composite for different combinations of the design variables and, thereby, to reduce efforts within production and experiments. In this way, it will be possible to direct the further material development. By common efforts of the experiments and numerical modeling the realistic and sufficient description of the thermo-mechanical behaviour of the composite microstructure was developed within this project. Experimental studies include material production, tensile and compression tests, thermal properties measurement, microscopic and microcomputer-tomographic studies. Results of these studies describing the material structure and properties were used as input or for the verification of the developed two scale numerical models. The modeling of the material behavior at the macroscale was provided by means of the finite element method. The effective properties of the single domains representing the microstructure on the microscale were calculated using the numerical homogenization procedure. For modeling of the thermo-mechanical properties of the MMCs at the microscale (single or poly-domain) different methods were used and compared. Firstly the semi-analytical models (e.g. Mori-Tanaka, self-consistent) and secondly 2D FE models based on the real microscopic images of the microstructure were used for the material modeling. The results obtained using these models were in good agreement with experimental results, but evident slight changes of the microstructure along the freeze-casting direction were not taking into account. The 3D representation of the domains by means of computer tomography of the ceramic preform were provided and after that directly utilized for creation of the 3D FE models of the real microstructure. Comparison of the obtained 3D properties shows that 2D models underestimate the elastic moduli and heat conduction and overestimate the thermal expansion. The suitable homogenization and modeling of the plastic flow in the metal and damage in the ceramics were proposed and applied for the modeling. Results of the calculations were compared with experimental results. Developed materials models were used for the microstructure optimization for different loading cases. Firstly the microstructure optimization for pure mechanical loading was provided for different behaviors of the phases: b) elastic of both phases, c) elastic for the ceramics and plastic for the metal and d) damage for the ceramics and plastic for the metal. The thermal and thermo-mechanical optimization was considered for three optimization problems: Firstly, the minimization of the highest local temperature (hot spot) for the heat conduction problem; secondly, the minimization of the effective thermal expansion for the thermo-elastic problem; finally, the proposed optimization procedures were extended for the solution of the multiphysics problem with two weaklycoupled fields (heat conduction and elasticity).
Projektbezogene Publikationen (Auswahl)
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Material parameter identification of interpenetrating metal-ceramic composites, Key Engineering Materials, 417-418: 53-56 (2010)
R. Piat, S. Roy, A. Wanner
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Multiscale homogenization models for the elastic behaviour of metal/ceramic composites with lamellar domains, Composite Science and Technology, 70(4): 664-670 (2010)
T. Ziegler, A. Neubrand, R. Piat
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Complete determination of elastic moduli of interpenetrating metal/ceramic composites using ultrasonic techniques and micromechanical modelling. Materials Science and Engineering: A, 528(28): 8226-8235 (2011)
S. Roy, J.-M. Gebert, G. Stasiuk, R. Piat, K. A. Weidenmann, A. Wanner
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Inelastic behavior of the single domain of metal-ceramic composites with lamellar microstructure. PAMM, Proc. Appl. Math. Mech. 11, 285-286 (2011)
Sinchuk, Y., Piat, R., Roy, S., Gibmeier, J., Wanner, A.
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Minimal compliance design for metal– ceramic composites with lamellar microstructures. Acta Materialia, 59(12):4835-4846 (2011)
R. Piat, Y. Sinchuk, M. Vasoya, O. Sigmund
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Optimal Elastic Design of CFCs. Key Engineering Materials, 488-489: 295-298 (2012)
G. Stasiuk, R. Piat, Y. Sinchuk
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Inelastic design of MMCs with lamellar micro structure. Developments in Strategic Materials and Computational Design IV, 34(10): 221-232 (2013)
Y. Sinchuk, R. Piat
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Numerical study of internal load transfer in metal/ceramic composites based on freeze-cast ceramic preforms and experimental validation, Materials Science & Engineering, A 585: 10–16 (2013)
Y. Sinchuk, S. Roy, J. Gibmeier, R. Piat, A. Wanner
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Thermal Conductivity Design for Locally Orthotropic Materials. Key Engineering Materials, 577-578: 437-440 (2014)
R. Piat, Y. Sinchuk
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Analysis of multiple cracking in metal/ceramic composites with lamellar microstructure, Arch. Appl-Mech
M. Kashtalyan, Y. Sinchuk, R. Piat , I. Guz
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Experimental and numerical determination of the elastic moduli of freeze cast MMC with different lamellae orientation. Ceramic Engineering and Science Proceedings 36(8): 153-168 (2015) [First Prize of Best Paper Awards, ICACC’15]
M. Merzkirch, Y. Sinchuk, K. A. Weidenmann, R. Piat
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Micro-Computed Tomography Image Based Numerical Elastic Homogenization of MMCs, Key Engineering Materials, 627: 437-440 (2015)
Y. Sinchuk, S. Dietrich, M. Merzkirch, K. Weidenmann, R. Piat
