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Microstructural stability of materials prepared by aditive manufacturing methods
Hyspecký, Michal ; Pantělejev, Libor (referee) ; Štěpánek, Roman (advisor)
This work deals with the microstructural thermal stability of material 2618 produced by the Selective Laser Melting metho - SLM. Microstructural stability is compared with the stability of material produced by conventional methods. Stability itself is evaluated by changes of microstructure and microhardness. The main finding is that the sample produced by SLM method reached a microhardness of 125 HV 0.3 and after sixteen hours of annealing at 200 °C a decrease of only a few units to 120 HV 0.3 was recorded. Based on the data obtained, it was concluded that the sample produced by SLM method is structurally stable, as it did not occur any significant changes in the microstructure or in the observed mechanical properties. As a result, components produced by SLM method become usable in operation in places with an elevated temperature up to 200 °C (with a given choice of criteria).
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Microstructural stability of materials prepared by aditive manufacturing methods
Hyspecký, Michal ; Pantělejev, Libor (referee) ; Štěpánek, Roman (advisor)
This work deals with the microstructural thermal stability of material 2618 produced by the Selective Laser Melting metho - SLM. Microstructural stability is compared with the stability of material produced by conventional methods. Stability itself is evaluated by changes of microstructure and microhardness. The main finding is that the sample produced by SLM method reached a microhardness of 125 HV 0.3 and after sixteen hours of annealing at 200 °C a decrease of only a few units to 120 HV 0.3 was recorded. Based on the data obtained, it was concluded that the sample produced by SLM method is structurally stable, as it did not occur any significant changes in the microstructure or in the observed mechanical properties. As a result, components produced by SLM method become usable in operation in places with an elevated temperature up to 200 °C (with a given choice of criteria).
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Microstructure, tensile properties and fatigue behaviour of bulk nanoquasicrystalline Al alloy Al93Fe3Cr2Ti2
Chlupová, Alice ; Chlup, Zdeněk ; Kruml, Tomáš ; Kuběna, Ivo ; Roupcová, Pavla
The characterization of mechanical properties (i.e. stress-strain characteristics measured in tensile and fatigue tests) together with description of the microstructure of bulk nanocrystalline Al alloy is reported. Aluminium based material used in this work was prepared by hot extrusion of gas atomised powder of chemical composition Al93Fe3Cr2Ti2 which contains nanosized quasicrystalline phase. Changes in fracture mechanisms both at fatigue testing performed at room temperature and at tensile tests performed at different test temperatures were investigated. The quality of powder compaction after extrusion was proved as sufficient. Strong texture in longitudinal direction resulting from production route was detected. Presence of icosahedral phase in material was confirmed by TEM and XRD techniques. Fractographical analysis of fracture surface was performed and results were used for description of fracture mechanisms.
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