National Repository of Grey Literature 7 records found  Search took 0.01 seconds. 
Influence of the electron beam trajectory on the surface properties of steel 42CrMo4
Mikuš, Tomáš ; Kouřil, Miloslav (referee) ; Foret, Rudolf (advisor)
The thesis deals with surface quenching of steel 42CrMo4 by electron beam. Influence of technologic parameters and beam deflection on properties and structure of prepared layers is studied. Electron beam surface quenching was applicated with and without melting of the surface. Structures of layers made by electron beam quenching were compared with structures made by laser and electromagnetic induction. Structures and phases were analysed by optical microscopy, SEM and roentgen diffraction. Hardness was measured on hardened layers.
The study of the spot size influence on the depth of hardening of the material 42CrMo4 during laser hardening
Kříž, Daniel ; Daněk, Ladislav (referee) ; Mrňa, Libor (advisor)
This master thesis is focused on surface hardening by using disk laser. Ten samples made of 42CrMo4 steel were hardened at varying speeds of quenching and diameter of the laser beam. The theoretical part initially describes the types of lasers. Further it describes methods of surface hardness processing such as kinds of hardening and chemical-thermal treatment, followed by description of the used material. Images of macrostructure, microstructure and compared values of hardness of single samples are evaluated in the experimental part. The thesis subsequently contains a technical-economic evaluation. Appropriate parameters for surface laser hardening are evaluated in the conclusion.
Surface Treatment Technology of Metallic Materials and its Applications using Electron Beam
Matlák, Jiří ; Dupák, Libor (referee) ; Houdková, Šárka (referee) ; Foret, Rudolf (advisor)
Fast deflection is one of the great advantages of an electron beam, making it possible to process a relatively large area at once and also to modify the distribution of the supplied energy. The dissertation deals with surface heat treatment with a focus on the effect of beam deflection on the process. Furthermore, the influence of processing speed and defocusing of the electron beam is studied. The principles of electron beam technology and the summary of surface heat treatment of various materials are presented in the literary part of the thesis. The experimental part is focused on the influence of process parameters on processing in the solid phase, carried out on steel 42CrMo4, and in in the liquid phase, carried out on alloy NiCrBSi. Especially changes in structure, hardness, shape of the processed area and wear resistance are evaluated on processed samples. The results are also evaluated from an energy perspective. Furthermore, an optimum combination of technological parameters is recommended for solid and liquid phase surface heat treatment.
Surface Treatment Technology of Metallic Materials and its Applications using Electron Beam
Matlák, Jiří ; Dupák, Libor (referee) ; Houdková, Šárka (referee) ; Foret, Rudolf (advisor)
Fast deflection is one of the great advantages of an electron beam, making it possible to process a relatively large area at once and also to modify the distribution of the supplied energy. The dissertation deals with surface heat treatment with a focus on the effect of beam deflection on the process. Furthermore, the influence of processing speed and defocusing of the electron beam is studied. The principles of electron beam technology and the summary of surface heat treatment of various materials are presented in the literary part of the thesis. The experimental part is focused on the influence of process parameters on processing in the solid phase, carried out on steel 42CrMo4, and in in the liquid phase, carried out on alloy NiCrBSi. Especially changes in structure, hardness, shape of the processed area and wear resistance are evaluated on processed samples. The results are also evaluated from an energy perspective. Furthermore, an optimum combination of technological parameters is recommended for solid and liquid phase surface heat treatment.
Influence of the electron beam trajectory on the surface properties of steel 42CrMo4
Mikuš, Tomáš ; Kouřil, Miloslav (referee) ; Foret, Rudolf (advisor)
The thesis deals with surface quenching of steel 42CrMo4 by electron beam. Influence of technologic parameters and beam deflection on properties and structure of prepared layers is studied. Electron beam surface quenching was applicated with and without melting of the surface. Structures of layers made by electron beam quenching were compared with structures made by laser and electromagnetic induction. Structures and phases were analysed by optical microscopy, SEM and roentgen diffraction. Hardness was measured on hardened layers.
Korozní degradace kovových materiálů
Kerber, Luboš
The thesis discusses the degradation of metallic materials in the salt spray. The work is focused on material 42CrMo4. From this steel are prepared test specimens for laboratory measurements. In the first part of the thesis is a theoretical and research described heat treatment, oxidation, mechanical and dynamic material testing, to be carried out on laboratory machines. The second part of the thesis is focused on processing the material to the required dimensions. Furthermore, the thesis deals with marking and heat treatment of the prepared sample and subsequent insertion into the prepared salt chamber. In the third part of the thesis is an analysis of the results that were obtained for samples prepared using laboratory testing, which were dynamic and mechanical tests.
The study of the spot size influence on the depth of hardening of the material 42CrMo4 during laser hardening
Kříž, Daniel ; Daněk, Ladislav (referee) ; Mrňa, Libor (advisor)
This master thesis is focused on surface hardening by using disk laser. Ten samples made of 42CrMo4 steel were hardened at varying speeds of quenching and diameter of the laser beam. The theoretical part initially describes the types of lasers. Further it describes methods of surface hardness processing such as kinds of hardening and chemical-thermal treatment, followed by description of the used material. Images of macrostructure, microstructure and compared values of hardness of single samples are evaluated in the experimental part. The thesis subsequently contains a technical-economic evaluation. Appropriate parameters for surface laser hardening are evaluated in the conclusion.

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