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Comparison of different approaches in ab initio modeling of mechanical and magnetic properties of materials
Čavojec, Martin ; Řehák, Petr (oponent) ; Zelený, Martin (vedoucí práce)
This thesis studies the influence of the quantum-mechanical description of interatomic interactions on the results of ab initio calculations of magnetic and mechanical properties of Fe, -TiAl and Ni2MnGa. Two methods for the description of interactions were examined, the projector-augmented wave method and the linear combination of atomic orbitals, implemented in ab initio codes VASP and SIESTA, respectively. The results of the dependence of the magnetic moments on the volume or tetragonal deformation paths indicate relative comparability across these two methods. However, calculated elastic constants also point to the unsuitability of the SIESTA software for calculations of elastic constants using the stress-strain method. Additionally, as a part of the thesis, a script for the calculation of elastic constants was created in the programming language Python.
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Tension - compression asymetry non-ferous alloys
Čavojec, Martin ; Judas, Jakub (oponent) ; Zapletal, Josef (vedoucí práce)
The Bachelor thesis focuses on asymmetric response to tensile and compressive loading of nonferrous metals, namely magnesium alloys. It describes basic principles of tensile and compressive testing; it expands on experimental determination of asymmetric response to tensile and compressive loading, influence of various parameters on tension-compression asymmetry, and possible description of asymmetry as a function of orientation and texture Towards the end, this thesis describes experimental determination and evaluation of asymmetric response to tensile and compressive loading of magnesium alloy AZ61, with metallographic analysis of this alloy.
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Comparison of different approaches in ab initio modeling of mechanical and magnetic properties of materials
Čavojec, Martin ; Řehák, Petr (oponent) ; Zelený, Martin (vedoucí práce)
This thesis studies the influence of the quantum-mechanical description of interatomic interactions on the results of ab initio calculations of magnetic and mechanical properties of Fe, -TiAl and Ni2MnGa. Two methods for the description of interactions were examined, the projector-augmented wave method and the linear combination of atomic orbitals, implemented in ab initio codes VASP and SIESTA, respectively. The results of the dependence of the magnetic moments on the volume or tetragonal deformation paths indicate relative comparability across these two methods. However, calculated elastic constants also point to the unsuitability of the SIESTA software for calculations of elastic constants using the stress-strain method. Additionally, as a part of the thesis, a script for the calculation of elastic constants was created in the programming language Python.
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Tension - compression asymetry non-ferous alloys
Čavojec, Martin ; Judas, Jakub (oponent) ; Zapletal, Josef (vedoucí práce)
The Bachelor thesis focuses on asymmetric response to tensile and compressive loading of nonferrous metals, namely magnesium alloys. It describes basic principles of tensile and compressive testing; it expands on experimental determination of asymmetric response to tensile and compressive loading, influence of various parameters on tension-compression asymmetry, and possible description of asymmetry as a function of orientation and texture Towards the end, this thesis describes experimental determination and evaluation of asymmetric response to tensile and compressive loading of magnesium alloy AZ61, with metallographic analysis of this alloy.
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