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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Depozice Al a AlN ultratenkých vrstev na křemíkový a grafenový substrát / The deposition of Al and AlN ultrathin layers on silicon and graphene substrate

Řihák, Radek January 2016 (has links)
This master's thesis deals with preparation and analysis of ultrathin films of aluminum and aluminum nitride. Films were prepared by effusion cells designed in previous bachelor's thesis. Cell construction and testing is included in this thesis. Behavior of aluminum on silicon dioxide, silicon and graphene was studied. Preparation of aluminum nitride by effusion cell and nitrogen ion source is described.
12

Mechanické vlastnosti hliníkové slitiny EN AW 7020 za zvýšených teplot / Mechanical properties Al-alloy EN AW 7020 at increase temperatures

Slouka, Marek January 2011 (has links)
The master’s thesis deals with high strength aluminium alloys AlZn4Mg (EN AW 7020). This alloy is used for high strength, low density, a good corrosion resistant and a good weldability in protective atmospheres. At first this thesis is described to aluminium alloys, ways of manufacturing and history. Next this thesis mainly deals with wrought aluminium alloys, heat treatment this alloys and alloys Al-Zn-Mg. Tensile tests were made of alloys EN AW 7020 at room temperature and increased temperature. Next this alloy was made of fatigue test and metallographic analysis. The model was construct. This model describe to behaviour alloy at increased temperature and this model was compared with measure values. This thesis describe to behaviour of study alloy at room temperature and increased temperature.
13

Zpracování Al-Sc hliníkové slitiny technologií SLM / Processing of Al-Sc aluminum alloy using SLM technology

Skulina, Daniel January 2017 (has links)
Master's thesis deals with the experimental determination of process parameters reaching densities >99 % for scandium modified aluminium alloy (Scalmalloy®) processed by SLM. The alloy achieves higher mechanical properties than the AlSi10Mg aluminum alloy commonly used. The theoretical part deals mainly with the results of Scalmalloy® alloys. Experimental bodies, testing methodology and evaluation method were designed on the basis of the theoretical parts,. The practical part is divided into four main stages: experimental determination of process parameters, a description of the effect of the parameters used on the relative density achieved, examination of the influence of process parameters on surface quality and mechanical testing. The mechanical properties were determined for the best parameters.
14

Intermetalické sloučeniny syntetizované in-situ v práškových materiálech / In-situ Synthesised Intermetallic Compounds in Powder Materials

Hanusová, Petra January 2018 (has links)
The mechanical treatment of solids is one of the most common and widely used operations. The volume of solids subjected to chemical treatment is very large too. Therefore, combining these two ways into one seems to be a logical solution. This method is called the mechanochemical processing of materials. Processing materials in this way has many advantages. On the one hand, this processing is economically as well as technologically feasible. Even the materials that not react together in conventional way can be prepare in this way. The mechanochemistry/mechanochemical synthesis utilizes the mechanical energy to activate chemical reactions and structural changes. The aluminothermic reduction reactions induced by the high – energy ball milling are gaining importance because of the potential applications like the synthesis of microcrystalline and nanocrystalline in – situ metal matrix composites. The mechanical activation of the chemical reactions by high energy ball milling often changes the reaction mechanism and produces metastable materials. Changes of reaction mechanisms during mechanical alloying on four different systems were studied. The system was based on this composition: Al - B2O3 - X (X = C, Ti, Nb, Cr). The possibility of another in – situ reactions during spark plasma sintering process (SPS) was also investigated. All systems were mechanically alloyed under the same conditions. After alloying, on each system scanning electron microscopy was performed and qualitative and quantitative analysis was performed using X-ray diffraction. The indentation hardness and the indentation modulus of elasticity were evaluated using nanoindentation. All analyzes were performed after mechanical alloying as well as SPS and the results were compared to each other. Based on the results, a change of reaction mechanisms was proposed for all systems. It has been found that metal matrix composites are formed and, when chromium is used, hybrid composite material reinforced with intermetallic phase and aluminum borate has been developed.
15

Využití CAM softwaru PowerMILL 2018 při obrábění páčky na motorku / Use of the CAM software PowerMILL 2018 for machining of a motorbike lever

Šprta, Pavel January 2019 (has links)
This diploma thesis deals with designing of manufacturing process of motorcycle lever prototype using PowerMILL 2018. The research part of the thesis contains analysis of materials used in the production of motorcycle levers and the introduction into CAD/CAM systems. The practical part contains choice of material, fixtures, cutting tools and solution of NC program itself. Summary of used strategies follows and ecenomical evaluation is performed at the end of the thesis.
16

Aplikace CAD/CAM softwaru hyperMILL při obrábění / Application CAD/CAM software hyperMILL for machining

Šebesta, Vít January 2019 (has links)
The main aim of this thesis is to acquire basic knowledge of CAM program hyperMILL 2019 with comparison of the ball nose end mill and circle segment end mill with taper form, economical evaluation and than make force analysis of specimen from aluminium alloy by milling with spindle moulder. Another aim of this thesis is also an analysis of force effects and force directions of the milling tool, advantages by using the circle segment end mill with taper form, the most common types of aluminium alloys and their mechanical properties and next comparison of CAM program hyperMILL with other selected program in the theoretic part.
17

Optimalizace tepelného zpracování odlitků ze slitin Al / "Optimizing the Al casting heat treatment"

Ostrézí, Barbora January 2019 (has links)
This master’s thesis focuses on the heat treatment of the aluminium alloy AlSi7Mg0,6 and also investigates the effects of different coolants usage on its mechanical properties. First part is dedicated to the description of aluminium alloys, their chemical composition, behaviour and mechanical properties with particular attention to the Al-Si-Mg alloys. This part was followed by the summary of commonly used heat treatment of aluminium alloys. The third part is dedicated to the experiment. Castings and test specimens were wax casted at Alucast, s.r.o. company. After annealing, the samples were quickly cooled down in four different coolants and underwent tensile testing. Their mechanical properties (tensile strength, yield point and ductility) were evaluated as well as microstructure. In the last part, the achieved results are presented.
18

Optimalizace výroby hliníkového odlitku s použitím numerické simulace / Optimization of aluminium casting process using numerical simulation

Kolařík, Martin January 2019 (has links)
The master’s thesis deals with the analysis of casting technology of the selected aluminium casting. It is a casting of a part of CNC milling machine and it is cast by gravity casting into a permanent mold. The defects which are the cause of a high percentage of nonconforming production were analyzed. Furthermore, the master’s thesis includes a complete analysis of filling and solidification of this casting in the ProCast simulation program. Numerical simulation results are verified and improved. Then the causes of problematic casting defects are proven on several calculated variants. Measures are proposed to minimize the tendency to produce castings with defects leading to nonconforming production.
19

Vliv řízeného naplynění hliníkových slitin na strukturu a vlastnosti odlitků / Influence of directed gassing of aluminium alloys on structure and properties of castings

Hotař, Jan January 2012 (has links)
This thesis examines the influence of directed gassing of aluminium alloys on structure and properties of castings. Cast and tests were made of gravity castings in metak molds. The aim is to compare the properties of castings and without the use of Probat-Fluss Mikro 100.
20

Hodnocení porezity u tlakově litých odlitků z Al slitin / Evaluation of porosity in Al-alloy die-castings

Havel, Jiří January 2012 (has links)
The aim of this diploma thesis is to analyse the porosity of die - cast cast that were made of the alloy AISi9u3 in iron-foundry Skoda Car Mlada Boleslav. The analysis and the sample comparisons are based on my own measurements and are also connected with previous diploma thesis which deals with that issue and was drawn up at Technical University in Brno. All measurements were statistically tested.

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