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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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Process Gas Heating Systems in Cold Spraying
Babinský, Tomáš ; Ing. Tomas Denk, Glass Service Inc., Vsetin, CR (referee) ; Čížek, Jan (advisor)
The goal of this bachelor's thesis is to present ways of gas heating used in the cold spray technology. Primarily the work is focused on description of currently-used techniques of high-pressure gas heating in cold spray and introduction to commercial products. Part of the work is dedicated to the gas temperature influence on the coating process. Gas heating methods in various industrial applications are summarized in the final chapter for potential use in cold spray technology.
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Effect of electron beam remeltin on binary mixtures deposited by the cold spray method
Novotný, David ; Řehořek, Lukáš (referee) ; Čupera, Jan (advisor)
This bachelor’s thesis deals with the effect of an electron beam remelting on binary mixtures of Fe-Al and Ni-Al, which were deposited by Cold spray. The Research study is focused on the basic principles of function and usage of the electron beam technology and the Cold spray method. Furthermore, binary systems of Fe-Al and Ni-Al are, along with their binary diagrams, also described in this part. In the Experimental part, the samples were remelted by an electron beam and consequently, the changes in microstucture were examined using electron and optical microscope.
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