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The development of multimaterial 3D printing of metal parts by SLM technology
Pliska, Jan ; Dočekalová, Kateřina (referee) ; Koutný, Daniel (advisor)
This thesis deals with research and optimization of process parameters and methodology of production of multimaterial parts manufactured by SLM. This work investigates iron-based and copper-based materials. The aim of the work is to create a good-quality horizontal and vertical multimaterial interface. In the case of the horizontal interface, the optimal process parameters for the processing of selected materials, their subsequent optimization for a goodquality horizontal interface and verification of mechanical properties were experimentally determined. For the vertical interface, it was necessary to design a production methodology and further optimize the process parameters. Finally, some mechanical properties of the interface were determined. However, research of the vertical interface has been a scientific task with some degree of uncertainty, and as this area has not yet been fully explored, it has proved to be a more complex problem than previously thought. It was therefore not possible to completely clarify it in the given time and with the available means. This work provides a detailed description of the mechanisms of creating both types of interfaces and their properties and can serve as a basis for further study of multimaterial 3D printing of metals based on iron and copper.
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The development of multimaterial 3D printing of metal parts by SLM technology
Pliska, Jan ; Dočekalová, Kateřina (referee) ; Koutný, Daniel (advisor)
This thesis deals with research and optimization of process parameters and methodology of production of multimaterial parts manufactured by SLM. This work investigates iron-based and copper-based materials. The aim of the work is to create a good-quality horizontal and vertical multimaterial interface. In the case of the horizontal interface, the optimal process parameters for the processing of selected materials, their subsequent optimization for a goodquality horizontal interface and verification of mechanical properties were experimentally determined. For the vertical interface, it was necessary to design a production methodology and further optimize the process parameters. Finally, some mechanical properties of the interface were determined. However, research of the vertical interface has been a scientific task with some degree of uncertainty, and as this area has not yet been fully explored, it has proved to be a more complex problem than previously thought. It was therefore not possible to completely clarify it in the given time and with the available means. This work provides a detailed description of the mechanisms of creating both types of interfaces and their properties and can serve as a basis for further study of multimaterial 3D printing of metals based on iron and copper.
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FITTING OF ELASTIC MODULUS ON THE INTERFACE BETWEEN TWO MATERIALS
Kocmanová, Lenka ; Materna, A. ; Haušild, P. ; Matějíček, Jiří
The paper is aimed to determinate of Young modulus near a sharp interface. The 3D elastic numeric model was used for prediction of the Young modulus. The simulated specimen was composed of tungsten and steel. The interface was plane which a normal vector was perpendicular to the indentation force. The indenter geometry for which numerical solutions were accomplished was a rounded cone indenter. An indentation depth is studied as function of a distance indenter-interface. The distance was normalized by depth of indentation. All values of Young modulus lay on one curve after distance normalization due to elasticity. The curve was fitted by inverse beta function. The curve determine the size of area of one material influenced by a second material.
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On an estimation of the exponent of the stress singularity: three dimensional problems and effect of residual stresses on a crack arrested on the interface
Máša, Bohuslav ; Náhlík, Luboš ; Hutař, Pavel
The main aim of this paper is an investigation of the crack behavior in the ceramics laminates. Especially, the problem of the estimation of the stress singularity exponent in such a material using different approaches is closely described. Since analytical approach is a suitable tool for two dimensional problems, introducing residual stresses, which can be result of used procedures during composite production, may influence value of the stress singularity exponent. Unfortunately, there is formally no analytical tool available to introduce residual stresses. Moreover, when the three dimensional geometry is investigated, effects of complicated stress distribution in front of the crack tip are of crucial importance for crack behavior. Hence using numerically obtained stress distribution appears to be the only way, how to capture the effect of residual stresses and three dimensional geometry of the crack front. The stress singularity exponent can be directly determined from stress components in front of the crack tip and/or from displacements at faces of the crack. Both can provide good results and give us a solution, which cannot be obtained analytically. In following text the procedure will be described in more detail and shown results obtained on ceramic laminate.
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The Influence of Multilayer Composite Interface on Crack Propagation Direction
Šestáková, Lucie ; Náhlík, Luboš ; Hutař, Pavel
The paper deals with crack propagation in multilayer composites. A substantial number of experimentally based works have indicated the changes in crack propagation direction on multilayer composite interfaces. Changes of this kind are mostly desirable for composite technical life extension. Crack direction modification in the composite interface is investigated through a numerical simulation of this problem. For determination of the consequent propagation direction the minimal strain energy density criterion is employed. The ascertained propagation direction of the crack in the multilayer composite is compared with experimental results.
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