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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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Reaction synthesis of bulk Fe-Al intermetallic materials
Dyčková, Lucie ; Hutařová, Simona (referee) ; Jan, Vít (advisor)
Bachelor’s thesis deals with iron aluminides. In literature analysis are the best known and the most widely used intermetallics materials, diffusion and other possible processing technologies of intermetallic materials. In experimental part was used sprayed coating. This sprayed coating was produced by cold gas-dynamic spray. In this thesis were analysed changes in microstructure of iron aluminides depending on annealing temperature. This thesis contains photographs of microstructure and analyses from electron microscopy and measurement of microhardness.
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Reaction synthesis of bulk intermetallic materials from kinetic spraying deposits
Stejskal, Pavel ; Roupcová, Pavla (referee) ; Jan, Vít (advisor)
This work deals with issues of preparation of intermetallics based on iron, nickel and titanium aluminides. It works with an idea of preparation of bulk material by reaction synthe-sis from kinetic spraying deposits by cold spray. Theoretical part is concerned with phases and compounds of these aluminides for structural applications, their characteristics and present fabrication. In experimental part there are studied microstructures created by annealing of deposits.
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Nanoscale AFM and TEM observations of elementary dislocation mechanisms
Veselý, Jozef ; Cieslar, Miroslav (advisor) ; Dlouhý, Antonín (referee) ; Novák, Pavel (referee)
Single crystals of iron with 20, 28 and 40 at. % aluminium were deformed in compression at room temperature. The later two alloys were deformed also at temperatures in the range of yield stress anomaly. Room temperature deformation was carried under the atomic force microscope (AFM) and the evolution of surface was recorded in-situ. Samples deformed at elevated temperatures were investigated by AFM after the deformation. Dislocation structures in deformed samples were then investigated in transmission electron microscope (TEM). Observations of surface (AFM) and bulk (TEM) are compared. Results of both techniques mutually agree and support the interpretation of observed phenomena. Several original analysis methods were developed. Most notably the stereographic reconstruction, which was applied to dislocation structures and carbide particles present in investigated alloys. Model explaining the distribution of carbide particle axes is presented. Powered by TCPDF (www.tcpdf.org)
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SPARK PLASMA SINTERING OF BALL MILLED AND ATOMIZED POWDER BASED ON Fe-Al
Šíma, V. ; Minárik, P. ; Chráska, Tomáš
High-quality compacts were prepared using the spark plasma sintering (SPS) method from powders of similar composition Fe-Al-Zr-B. The properties of the sintered compacts are strongly dependent on the morphology and properties of the feedstock powder. The first powder was obtained by ball milling of the as cast alloy and the second was prepared by atomization under argon atmosphere. The morphology and structure of the two powders are compared and mechanical properties and microstructure of compacts prepared under the same conditions of the SPS procedure are discussed. The milled powder has an irregular morphology and shape of the polycrystalline particles, which have a completely disordered BCC structure with considerable internal stresses, high concentration of structural defects and the presence of aluminum oxide. The atomized powder particles are nearly spherical, polycrystalline with ordered B2 structure, with no significant signs of internal stresses and oxidation. Microhardness of particles of both powders was measured and compared with the microhardness of compact materials, the results of compression tests of compacts at room temperature were compared and discussed.
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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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Reaction synthesis of bulk intermetallic materials from kinetic spraying deposits
Stejskal, Pavel ; Roupcová, Pavla (referee) ; Jan, Vít (advisor)
This work deals with issues of preparation of intermetallics based on iron, nickel and titanium aluminides. It works with an idea of preparation of bulk material by reaction synthe-sis from kinetic spraying deposits by cold spray. Theoretical part is concerned with phases and compounds of these aluminides for structural applications, their characteristics and present fabrication. In experimental part there are studied microstructures created by annealing of deposits.
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Reaction synthesis of bulk Fe-Al intermetallic materials
Dyčková, Lucie ; Hutařová, Simona (referee) ; Jan, Vít (advisor)
Bachelor’s thesis deals with iron aluminides. In literature analysis are the best known and the most widely used intermetallics materials, diffusion and other possible processing technologies of intermetallic materials. In experimental part was used sprayed coating. This sprayed coating was produced by cold gas-dynamic spray. In this thesis were analysed changes in microstructure of iron aluminides depending on annealing temperature. This thesis contains photographs of microstructure and analyses from electron microscopy and measurement of microhardness.
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