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The material base of trial bicycles
Debs, Martin ; Hanusová, Petra (referee) ; Jan, Vít (advisor)
This bachelor thesis is focused on the material analysis of trial bicycle parts. The main aim is the summary of materials and technologies used in construction of these bicycles, exploiting knowledge of material microstructure theory, both in theoretical and practical sections of the thesis. To attain the aims, it was necessary to perform a proper metallographic specimen preparation. These specimens allowed to observe a material microstructure of various bicycle parts and demonstrate the use of metallographic techniques for determining the type of the used materials and applied processing technologies. Comprehensive metallographic analysis proved the use of materials in ordinary quality and ordinary technological processes. Subsequently we documented and explicated various defects in microstructure of the examined parts.
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Metallography of stainless steels
Hasoňová, Michaela ; Kalina, Lukáš (referee) ; Zmrzlý, Martin (advisor)
This thesis deals with metallography of stainless steels. At the beginning of theoretical part the history of metallography is shortly summarized. Then the basic knowledge about metallography, ways and methods of preparing samples for subsequent analysis of structure are resumed. There are also summarized methods for examining the macrostructure and microstructure of materials with a particular focus on stainless steels. The literary-search section summarizes recent advances in the study of the structure of materials using methods of metallography. The task of the study was to find suitable composition of etchant to reveal the structure of stainless steels in order to achieve high quality and especially reproducible results.
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Magnesium alloys
Březina, Matěj ; Šoukal, František (referee) ; Zmrzlý, Martin (advisor)
The study is focused on corrosion and corrosion protection of magnesium and magnesium alloys. The theoretical part describes properties of magnesium and magnesium alloys. It shows their advantages as well as their disadvantages and discusses ideal use for these alloys. The theoretical part analyses basic corrosion characteristics and typical corrosion processes. It deals with types of corrosion protection and ways of its use. The experimental part was focused on metallographic analysis and corrosion behavior of magnesium alloy AZ91. Metallographic methods were used for preparing AZ91 to corrosion tests. The experimental part compared corrosion rate and degradation of pure AZ91 and AZ91 with conversion coating (phosphate-permanganate) in 3,5% sodium chloride solution in times: 1, 8 and 48 hours.
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Reactivity and controll of properties of metallic materials
Ševčíková, Barbora ; Opravil, Tomáš (referee) ; Zmrzlý, Martin (advisor)
The main objective of the bachelor thesis is to investigate the reactivity and corrosion of materials, namely of magnesium alloys. The theoretical part comprises a brief summary of the existing knowledge on magnesium alloys in the field of metal corrosion and a description of essential properties of the examined and utilized material. These are followed by the protection technology and a material resistance analysis including the specification of the processes applied in the experimental part. The thesis is focused on a comparison of the microstructure and corrosion resistance of magnesium alloys AZ31, AZ61 and AZ91. The applied methodology lied on metallography preparation of light optical micrographs of the surface-region cross-sections and on corrosion tests. These were carried out in 3% sodium chloride solution where the samples were immersed for the period of 8 hours.
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Kvalita svarových spojů
Pénz, Attila
The thesis may be divided into two parts, the theoretical and practical part. In the theoretical part of my thesis describe the permanent connection in engineering includes soldering, gluing, riveting and welding and further describe the building-up and weldability tests as part of the technological tests. In the practical part of my thesis describe what and how I was doing. How I progressed in the production of individual samples and testing. We can find there a description of the tensile test, graphical display each tensile test, measured and calculated values and evaluation of tests. Further describe the detection of microstructure and microhardness. Each photo of microstructure I worked to the table and commented what can we see on them. At microhardness we can read about the gist and execution of the test. Obtained values I compiled to the chart and commented. According to the hardness can recognize a structural component and phases. In conclusion is a summary of the measured values and evaluation.
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