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Optimizing the Properties of the Coatings prepared by the Cold Spray Method using Heat Treatment
Bartošík, Vojtěch ; Šmíd, Miroslav (referee) ; Hutařová, Simona (advisor)
This bachelor's thesis deals with the choice of heat treatment parameters of the metal coating of austenitic unstabilized stainless steel AISI 304L applied by the Cold spray method. With the help of suitable heat treatment, it is possible to adjust the mechanical properties, reduce the porosity and, last but not least, also remove high residual stresses in the material. The theoretical part of the work is devoted to literature research on the topic of Cold spray technology, corrosion and corrosion-resistant steels. The experimental part describes the procedures for measuring samples that have undergone heat treatment. This took place in the temperature range of 500 to 1100 °C, always with an hour's holding time at the temperature, followed by cooling in air. In addition to these samples, the material was also examined in its initial state. Porosity, microhardness and also magnetism were determined. To analyze the structure, photographs were taken on a light and electron scanning microscope. Based on the results, heat treatment with an hourly hold at 700 °C seems to be a good choice, where a significant decrease in porosity, partial recovery of the structure while maintaining high microhardness and also grain fineness was observed.
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Influence of Process Parameters and Heat Treatment on the Structure and Properties of Cold Spray Method
Lindner, Patrik ; Řehořek, Lukáš (referee) ; Hutařová, Simona (advisor)
The bachelor thesis is a research of the state of knowledge focused on Cold spray technology and process parameters affecting the properties of coating, such as pressure, temperature, nozzle speed, sequence of individual layers, size of powder and others. This technology uses the kinetic energy of the impact of particles on the substrate. The main advantage of this method is possibility of forming a coating of large thicknesses (in millimeters) without oxides, with relatively low porosity and favourable mechanical properties. Aim of this work is to get acquainted with the Cold spray technology and the influence of process parameters on the quality of the spray. The influence of process parameters on properties is also demonstrated by own experimental results.
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Reaction synthesis of bulk intermetallic materials from cold spray deposits from binary powders containing iron
Dyčková, Lucie ; Krajňáková, Petra (referee) ; Jan, Vít (advisor)
This thesis deals with reaction synthesis of materials Fe–Al, Fe–Cu and Fe–Ni from cold spray. In literature analysis are introduced these systems and for each system there is brief description of binary equilibrium diagram. Furthermore here are some short explanations of diffusion, Kirkendall effect and other possible processing technologies of intermetallic materials. In experimental part, samples of sprayed materials were annealed and then microstructural changes were investigated. This thesis contains photographs of microstructure, results from scanning electron microscopy, X-ray, and measurements of microhardness.
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Modification of HVOF and cold spray deposited coatings via electron beam technology
Vacek, Petr ; Šiška, Filip (referee) ; Čížek, Jan (advisor)
The aim of this thesis was to modify microstructure and coating-substrate interface of CoNiCrAlY coatings deposited by HVOF and cold spray on Inconel 718 substrates. Electron beam remelting and annealing in a protective atmosphere were used to modify the coatings. Microstructure, chemical and phase composition were analyzed. The effect of beam current, transversal velocity and beam defocus on remelted depth was evaluated. As-sprayed microstructure and chemical composition of coatings were analyzed and compared with remelted samples. The effect of annealing of the as-sprayed and remelted samples was evaluated. Remelted layers exhibited dendritic structure. Chemical composition changed only after remelting of interface and part of a substrate. When only the coating was remelted, chemical composition remained the same. Phases coarsened after the annealing. Chemical composition changed after annealing due to the diffusion.
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Properties of Metallic Materials Prepared by Cold Spray Technology
Piňos, Jakub ; Šiška,, Filip (referee) ; Čížek, Jan (advisor)
Cold spray is a novel coating method. Due to its low-temperature character, it has a potential to replace the high-temperature thermal spray processes in some applications. The presented work analyzes the microstructure and the phase composition of pure metal coatings deposited by cold spraying and evaluates selected mechanical properties. Specimens prepared by readily used HVOF industrial technology were used for comparison purposes.
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Determination of properties of as-sprayed and EB-deposited coatings prepared by thermal spray technologies using scratch test and nano-indentation methods
Cének, Lukáš ; Tkachenko, Serhii (referee) ; Čížek, Jan (advisor)
Properties of samples and their coatings may be affected by the electron beam. This paper deals with the analysis of the microstructure, phase and chemical composition and the determination of mechanical characteristics of inconel steel substrate and CoNiCrAlY coatings deposited via different types of thermal spraying (HVOF, cold spray), in combination with modifications by the electron beam technology. During the study it was found that the deposition did not change the chemical composition. Further it was found that the interaction of the electron beam with the material did not change the chemical composition, but there is a change in the structure and a reduction of porosity and surface roughness, resulting in a change of mechanical properties such as decreasing hardness or increase of the modulus of elasticity.
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The use of surface modification for enhancing mechanical properties of SLM bulk materials
Barinka, Michal ; Řehořek, Lukáš (referee) ; Jan, Vít (advisor)
This diploma thesis deals with the surface modification of 3D printed metallic materials. The research part presents the most used methods of additive manufacturing and their process parameters influencing the quality of printed components. Defects arising during these processes and the techniques used to eliminate them are also described. In the experimental part of the work, the optimization of electrochemical polishing parameters was performed. The aim was to modify the rough surface of the components and thus prevent the formation of defects on the surface. The mechanical properties were investigated by means of three-point bending under static and dynamic loading. Fractographic analysis was performed on the quarry surfaces.
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Multimaterial structures preparation by using deposition methods
Novotná, Hana ; Čupera, Jan (referee) ; Řehořek, Lukáš (advisor)
This master’s thesis deals with origin, structure and mechanical properties of architectured material. The theoretical part deals with composits and theory of architectured materials. Further, the cold spray technology is described and it is used to create the network of grooves in the architectured material. In the experimantal part the influence of groof geometry and profil on the mechanical properties of the resulting architectured material is researched. Microstructure and hardness of the samples were also examined.
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Cold Spray coatings on high strength steels
Šesták, Stanislav ; Čupera, Jan (referee) ; Řehořek, Lukáš (advisor)
This bachelor’s thesis focuses on possible applications of the Cold Spray additive technology in context of high strength steels. The theoretical part of this work represents an extensive research on the topic of Cold Spray technology, showing connections between many of the mechanisms of this technology. This part also focuses specifically on high strength steels, their types, microstructures and properties. The experimental part of this work examines four samples of Cold Spray coatings on a high strength steel. After depositing these coatings, microstructure and microhardness analysis are provided.
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Properties of Inconel alloy coating on austenitic steel made by cold-spray technology after electron beam remelting
Chlupová, Monika ; Řehořek, Lukáš (referee) ; Foret, Rudolf (advisor)
This diploma thesis is focused on description of the properties of a layer of Inconel 718 applied on austenitic steel AISI 304 by the Cold Spray and subsequently remelted by electron beam. The first part presents the Cold Spray with its properties, advantages and disadvantages, and also describes the principle of electron beam remelting and other possible uses of electron beam, for example welding, drilling, heat treatment etc. The second part describes the material and the methods used for the preparation and evaluation of the samples. There are evaluated the porosity, microstructure and microhardness of the layers applied by the Cold Spray and these properties are further compared with the properties of the same layers remelted by electron beam. In conclusion, the results of the porosity of the layers applied by the Cold Spray are discussed with the literature and the results of electron beam remelting are only partially described here, because it was not possible to find literature about this topic. There are also suggestions for further research of the properties of this layers, which is necessary to know before implementing this method of producing layers for commercial production.
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