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Evaluation of Surface Layers of Ball and Sliding Bearings Components
Šafář, Martin ; Hutařová, Simona (referee) ; Doležal, Pavel (advisor)
This bachelo’s thesis solve the problems abrasion film bearing. The purpose of this thesis was used four type film, ISOFLON, Xylan 1010, DLC a PTFE + Niborit 5P.By one of tendenci is specifi coefficient friction over tribological test. On the next tendenci was size film for and after a tribological test find, elese size abrasion. Was make chemical analyse of all film.To elements interaction study light microscopy, scanning electron microscopy equipped by energy dispersive mikroanalyses.
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Modern methods of polymers characterisation
Ropek, Lukáš ; Klakurková, Lenka (referee) ; Hutařová, Simona (advisor)
The bachelor thesis consists of an overview of modern methods of polymers testing. The first part deals with historical development, various types and synthesis of polymers. Further work is focused on the structure of polymers, a description of modern sample preparation methods and methods of study the polymers structure. Next, the mechanical properties of polymers and methods of testing the mechanical properties are discussed. Finally, the work is focused on material resistance testing of polymer pipes used in current practice.
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Fatigue behaviour of nickel-based superalloy IN738LC with AlSi coating at 800°C
Hlavnička, Radek ; Juliš, Martin (referee) ; Hutařová, Simona (advisor)
This work deals with influence of applied protective AlSi layer on low cycle fatigue behaviour of substrate from nickel base superalloy Inconel 738 LC. Protective layer is made by thermal spraying, plasma spraying followed by heat treatment. The emphasis is especially concentrated to the microstructure evaluation of the protect layer and basic material, in addition, measurement of layer thickness and the microhardness in as sprayed conditions and after heat treatment. The fatigue behaviour is assessed by fracture area observation and fatigue cracks evaluation after low cycle fatigue tests carried out at 800 °C.
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Fatigue failure mechanism of nickel-based superalloy Inconel 713LC under 800°C
Smékalová, Jana ; Juliš, Martin (referee) ; Hutařová, Simona (advisor)
Nickel superalloys are used for high-temperature application in energetic and aerospace industry. They are exposed to aggressive environment at high temperatures with the interactions between fatigue and creep processes, high-temperature oxidation, corrosion and erosion. Lifetime extension of such strained parts while increasing the performance of particular machine is possible by applying protective surface coatings. The subject of this work is to investigate the fatigue failure mechanisms of superalloy Inconel 713LC at 800 °C and to compare these mechanisms between material with a protective coating based on Al-Si and material without coating. The location of initiation fatigue cracks, their propagation and the fatigue crack propagation rate in some areas were analyzed by optical microscopy, scanning electron microscopy and confocal laser scanning microscopy. Based on previous research it was found that the application of the coating AlSi has a positive effect on lifetime of alloy Inconel 713LC. These results were confirmed and estimated in the diploma thesis.
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Wood - structural material, its structure and mechanical properties
Kundela, Miroslav ; Hutařová, Simona (referee) ; Klakurková, Lenka (advisor)
The aim of proposed work is focused on the classification of wood using several different perspectives. Especially, with focus on its macro-, micro-structure (plant cell, wood cell and anatomical structure), chemical composition, physical properties (density, thermal properties, moisture, sound and electrical) and mechanical properties (strength, hardness and technological properties).
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Weldability of steels for steam turbine parts
Jech, David ; Hutařová, Simona (referee) ; Juliš, Martin (advisor)
The aim of contemporary standard welding technologies is to create compact welds with high value of solidity and toughness in laboratorial and operational conditions. This welding technology is asserted in new creep - resisting steels on basis of steel CrMoV and CrMoNiV, which have high value of solidity and creep - resistance. The thesis deals with problems connected with the weldability of steels for steam turbine rotors and it´s aim is to interpret the structural and mechanical features of the weld joint for material combinations under consideration. For the assessment of weld joint features has been used measuring of micro hardness and hardness according to Vickers, microstructure was observed by methods of light microscopy.
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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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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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Structure and mechanical properties of magnesium materials prepared by SPS
Pleskalová, Kateřina ; Hutařová, Simona (referee) ; Doležal, Pavel (advisor)
This diploma thesis deals with the processing of the magnesium-based powder materials with the addition of zinc by the spark plasma sintering. The aim of this thesis is to evaluate influence of sintering parameters and zinc content on the microstructure and mechanical properties of the material. First part of the thesis is literary research which is divided into two main chapters. The first chapter describes magnesium-based materials and mentions their use as biomaterials. The second chapter discusses powder metallurgy, specifically magnesium powders and spark plasma sintering. In the experimental part the powders were sintered at temperatures 300 °C and 400 °C and an analysis was performed using optical microscope, scanning electron microscope, then also EDS analysis and hardness, microhardness and three-point bending tests were performed. An increase in hardness was observed with increasing zinc content and with increasing sintering temperature. The flexural strength was higher for materials sintered at a temperature of 400 ° C.
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Structure and Properties of Cast Nickel-base Superalloys
Fukátková, Pavla ; Němec, Karel (referee) ; Hutařová, Simona (advisor)
This thesis is focused on changes of microstructure of nickel - base superalloys (alloy ZH6K) from the point of view of quantitative and qualitative classification. These phases especially phase ´ and the carbides significantly influence mechanical and other characteristics during the strain and temperature load action. Specimens were observed after thermal and thermal-strain exposition by light microscope and by scanning electrone microscope. There was used the image analysis for the following classification. The part of the thesis is the theoretical summary of the microstructure, chemist and the characteristic of the nickel - base superalloys.
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