Numerical modelling of grain refinement around highly reactive interfaces in processing of nanocrystallised multilayered metallic materials by duplex technique

Microstructure evolution around highly reactive interfaces in processing of nanocrystallised multilayered metallic materials have been investigated and discussed in the present work. Conditions leading to grain refinement during co-rolling stage of the duplex processing technique are analysed using the multi-level finite element based numerical model combined with three-dimensional frontal cellular automata. The model was capable to simulate development of grain boundaries and changes of the boundary disorientation angle within the metal structure taking into account crystal plasticity formulation. Appearance of a large number of structural elements, identified as dislocation cells, sub-grains and new grains, has been identified within the metal structure as a result of metal flow disturbance and consequently inhomogeneous deformation around oxide islets at the interfaces during the co-rolling stage. These areas corresponded to the locations of shear bands observed experimentally using SEM-EBSD analysis. The obtained results illustrate a significant potential of the proposed modelling approach for quantitative analysis and optimisation of the highly refined non-homogeneous microstructures formed around the oxidised interfaces during processing of such laminated materials

Time measurement of simple CA and FCA

The project was created in Visual Studio using C++, CUDA, and OpenGL.The aim is to measure and compare the calculation time of different cellular automata: two classical CA (CCA) and two frontal (FCA).It contains also figures, which are helpful for adjustment of the project, and an Excel file with the results of time measurements.The size of modeled space is set in FCA.cuh.The simulation cases are set in FCA.cu in the subroutines void CA() and __global__ void CA_P() for sequential and parallel calculations appropriated

Time measurement of simple CA and FCA

The project was created in Visual Studio using C++, CUDA, and OpenGL.The aim is to measure and compare the calculation time of different cellular automata: two classical CA (CCA) and two frontal (FCA).It contains also figures, which are helpful for adjustment of the project, and an Excel file with the results of time measurements.The size of modeled space is set in FCA.cuh.The simulation cases are set in FCA.cu in the subroutines void CA() and __global__ void CA_P() for sequential and parallel calculations appropriated.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Modeling with FCA-Based Model of Microstructure Evolution of MgCa08 Alloy During Drawing of Thin Wire in Heated Die / Modelowanie Za Pomocą FCA Rozwoju Mikrostruktury Stopu MgCa08 Podczas Ciągnienia Cienkiego Drutu W Podgrzewanym Ciagadle

The paper deals with a modeling of manufacturing process of thin wire of MgCa08 alloy used as biocompatible soluble threads for medical application. Some difficulties in material deformation subjected with its hexagonal structure can be solved with accurate establishment of the deformation conditions, especially temperature history of the whole process. In drawing process with heated die, wire is preheated in furnace and then deformed. The only narrow temperature range allows for multi-pass drawing without wire breaking. Diameter below 0.1 mm required for the final product makes very important the consideration of microstructure evolution because grain size is comparable with the wire dimensions. For this reason the problem is considered in the micro scale by using the frontal cellular automata (FCA)-based model. The goals of present work are the development and validation of FCA-base model of microstructure evolution of MgCa0.8 magnesium alloy. To reach this objective, plastometric and relaxation tests of MgCA08 alloy were done on physical simulator GLEEBLE 3800. Results of the experimental studies were used for parameters identification of the hardening-softening model of the material. Then, initial microstructure and its evolution during the drawing passes were simulated with FCA-based model. FCA consider dislocation density and flow stress, hardening and softening including recovery and recrystallization, grain refinement and grain rotation, as well as grain growth. It allows one to obtain structures close to real ones. Two variants of the drawing process with different temperature history were considered. The deformation scheme was the same. Simulation results with following short discussion confirm usefulness of FCA-based model for explanation and selection of rational technological condition of thin wire drawing of MgCa08 alloy.W pracy rozpatrzono proces wytwarzania cienkich drutów z biozgodnego stopu MgCa0.8 z przeznaczeniem na resorbowalne nici chirurgiczne. W procesie ciągnienia drut nagrzewany jest w piecu a następnie odkształcany. Jednym z warunków, jaki musi być spełniony w technologicznym procesie jest zachodzenie rekrystalizacji w trakcie ciągnienia. Pozwala to na realizację wielo przepustowego procesu ciągnienia bez wyżarzania międzyoperacyjnego. Prognozowanie rekrystalizacji na etapie projektowania technologii wymaga stworzenia modelu rekrystalizacji. W przypadku ciągnienia drutów o średnicach mniejszych niż 0.1 mm konieczne jest zastosowania modelu w skali mikro. Celem pracy jest opracowanie modelu rekrystalizacji, opartego o frontalne automaty komórkowe (FCA) oraz przykładowa symulacja kilku przepustów ciągnienia. Do kalibracji modelu FCA wykorzystano badania plastometryczne oraz testy relaksacji stopu MgCa08 przy użyciu symulatora fizycznego GLEEBLE 3800. Wyniki tych badań pozwoliły wyznaczyć parametry modelu umocnienia-mięknięcia materiału. Następnie początkowa mikrostruktura i jej rozwój podczas procesu ciągnienia były analizowane za pomocą modelu opartego o FCA, który uwzględnia gęstość dyslokacji, naprężenie uplastyczniające, umocnienie i mięknięcie w tym zdrowienie i rekrystalizację, rozdrobnienie ziaren oraz ich rotację i rozrost, co pozwala na uzyskanie struktury bliskiej do rzeczywistej. Dwa warianty procesu ciągnienia o różnej historii zmiany temperatury rozpatrzono w pracy. Wyniki symulacji potwierdziły przydatność modelu opartego o FCA do uzasadnienia i wyboru racjonalnych warunków technologicznych ciągnienia cienkich drutów za stopu MgCa08. W pracy przedstawiono również praktyczną implementację procesu ciągnienia

Modelowanie za pomocą FCA rozwoju mikrostruktury stopu MgCa08 podczas ciągnienia cienkiego drutu w podgrzewanym ciągadle

The paper deals with a modeling of manufacturing process of thin wire of MgCa08 alloy used as biocompatible soluble threads for medical application. Some difficulties in material deformation subjected with its hexagonal structure can be solved with accurate establishment of the deformation conditions, especially temperature history of the whole process. In drawing process with heated die, wire is preheated in furnace and then deformed. The only narrow temperature range allows for multi-pass drawing without wire breaking. Diameter below 0.1 mm required for the final product makes very important the consideration of microstructure evolution because grain size is comparable with the wire dimensions. For this reason the problem is considered in the micro scale by using the frontal cellular automata (FCA)-based model. The goals of present work are the development and validation of FCA-base model of microstructure evolution of MgCa0.8 magnesium alloy. To reach this objective, plastometric and relaxation tests of MgCA08 alloy were done on physical simulator GLEEBLE 3800. Results of the experimental studies were used for parameters identification of the hardening-softening model of the material. Then, initial microstructure and its evolution during the drawing passes were simulated with FCA-based model. FCA consider dislocation density and flow stress, hardening and softening including recovery and recrystallization, grain refinement and grain rotation, as well as grain growth. It allows one to obtain structures close to real ones. Two variants of the drawing process with different temperature history were considered. The deformation scheme was the same. Simulation results with following short discussion confirm usefulness of FCA-based model for explanation and selection of rational technological condition of thin wire drawing of MgCa08 alloy.W pracy rozpatrzono proces wytwarzania cienkich drutów z biozgodnego stopu MgCa0.8 z przeznaczeniem na resorbowalne nici chirurgiczne. W procesie ciągnienia drut nagrzewany jest w piecu a następnie odkształcany. Jednym z warunków, jaki musi być spełniony w technologicznym procesie jest zachodzenie rekrystalizacji w trakcie ciągnienia. Pozwala to na realizację wielo przepustowego procesu ciągnienia bez wyżarzania międzyoperacyjnego. Prognozowanie rekrystalizacji na etapie projektowania technologii wymaga stworzenia modelu rekrystalizacji. W przypadku ciągnienia drutów o średnicach mniejszych niż 0.1 mm konieczne jest zastosowania modelu w skali mikro. Celem pracy jest opracowanie modelu rekrystalizacji, opartego o frontalne automaty komórkowe (FCA) oraz przykładowa symulacja kilku przepustów ciągnienia. Do kalibracji modelu FCA wykorzystano badania plastometryczne oraz testy relaksacji stopu MgCa08 przy użyciu symulatora fizycznego GLEEBLE 3800. Wyniki tych badań pozwoliły wyznaczyć parametry modelu umocnienia-mięknięcia materiału. Następnie początkowa mikrostruktura i jej rozwój podczas procesu ciągnienia były analizowane za pomocą modelu opartego o FCA, który uwzględnia gęstość dyslokacji, naprężenie uplastyczniające, umocnienie i mięknięcie w tym zdrowienie i rekrystalizację, rozdrobnienie ziaren oraz ich rotację i rozrost, co pozwala na uzyskanie struktury bliskiej do rzeczywistej. Dwa warianty procesu ciągnienia o różnej historii zmiany temperatury rozpatrzono w pracy. Wyniki symulacji potwierdziły przydatność modelu opartego o FCA do uzasadnienia i wyboru racjonalnych warunków technologicznych ciągnienia cienkich drutów za stopu MgCa08. W pracy przedstawiono również praktyczną implementację procesu ciągnienia

Development of the multi-scale analysis model to simulate strain localization occurring during material processing

Abstract A detailed description of possibilities given by the developed Cellular Automata&mdash;Finite Element (CAFE) multi scale model for prediction of the initiation and propagation of micro shear bands and shear bands in metallic materials subjected to plastic deformation is presented in the work. Particular emphasis in defining the criterion for initiation of micro shear and shear bands, as well as in defining the transition rules for the cellular automata, is put on accounting for the physical aspects of these phenomena occurring in two different scales in the material. The proposed approach led to the creation of the real multi scale model of strain localization phenomena. This model predicts material behavior in various thermo-mechanical processes. Selected examples of applications of the developed model to simulations of metal forming processes, which involve strain localization, are presented in the work. An approach based on the Smoothed Particle Hydrodynamic, which allows to overcome difficulties with remeshing in the traditional CAFE method, is a subject of this work as well. In the developed model remeshing becomes possible and difficulties limiting application of the CAFE method to simple deformation processes are solved. Obtained results of numerical simulaA detailed description of possibilities given by the developed Cellular Automata&mdash;Finite Element (CAFE) multi scale model for prediction of the initiation and propagation of micro shear bands and shear bands in metallic materials subjected to plastic deformation is presented in the work. Particular emphasis in defining the criterion for initiation of micro shear and shear bands, as well as in defining the transition rules for the cellular automata, is put on accounting for the physical aspects of these phenomena occurring in two different scales in the material. The proposed approach led to the creation of the real multi scale model of strain localization phenomena. This model predicts material behavior in various thermo-mechanical processes. Selected examples of applications of the developed model to simulations of metal forming processes, which involve strain localization, are presented in the work. An approach based on the Smoothed Particle Hydrodynamic, which allows to overcome difficulties with remeshing in the traditional CAFE method, is a subject of this work as well. In the developed model remeshing becomes possible and difficulties limiting application of the CAFE method to simple deformation processes are solved. Obtained results of numerical simulations are compared with the experimental results of cold rolling process to show good predicative capabilities of the developed model.tions are compared with the experimental results of cold rolling process to show good predicative capabilities of the developed model.<br /