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The Material Selection for Bicycle Frames
Šály, Peter ; Petrenec, Martin (referee) ; Němec, Karel (advisor)
Bachelor's thesis summarises basic information about materials that are used for production of bicykle's frames. It concerns not only with common materials that are the most used nowadays, thus aluminium alloys and composite materials – carbon in the concrete, but it also pointed on the other, alternative materials. It also explains specific terms that relate to concrete materials or to their technological treating. Each material has listed characteristic which is objective thus measurable and it results from physical-chemical's properties and treating possibilities of concrete materials. It conveys assumption of frame behaviour made from this material. Subjective characteristic is also listed and it results from practice – from the feelings by real ride. Comparison of these two approaches resulted in conclusion which may help in choosing material for bicykle's frame which we have specific requirements on. Next thesis concerns with usage of concrete materials by various producers whether world producers or national ones, with orientation on brands which are interesting because of their treating of unusual materials or they are interesting because of their specific treating of common materials. There is a brief review of most used materials for concrete types of bicycle's frames at the end of the thesis.
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Heat treatment of aluminum alloys
Adami, Martin ; Čupera, Jan (referee) ; Němec, Karel (advisor)
This bachelor theses deals with description aluminium alloys, theirs applications in engineering and theirs heat treatment. First part is focused on pure aluminium and its production. The other one is about distribution aluminium alloys by possibility of precipitation hardening.
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Influence of filters on running of metal flow
Makalouš, Jakub ; Veverka, Aleš (referee) ; Roučka, Jaromír (advisor)
This study deals with influence of filters on running of aluminum metal flow. The main objective was to describe hydraulic resistances of assorted filters and running of silting filters by inclusions. Theoretical part generally describes filtration process and also filtration from the point of view of aluminum alloys and the most important characteristics of each type of alumina inclusions. Experimental part deals with flow rate tests, influence of filters on gassiness of melt and metallographic analysis. It was find out, that filter GEPHAL made minimal hydraulic resistance, on the other hand ceramic foam filters type LD made the maximal hydraulic resistance. It is necessary to reduce filtration surface for study running of silting filters by inclusions. Metallographic analysis showed amorphous alumina film inclusions, spinell Al2O3.2MgO, sludge and carbide of silicon.
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Reactivity and controll of properties of metallic materials
Kouba, Jan ; Richtera, Lukáš (referee) ; Zmrzlý, Martin (advisor)
This study deals with properties of aluminum alloys that are used in aerospace industry, particularly with alloy 2024. In introduction, the fundamental questions of metallurgy of aluminum alloys and their basic properties are summarized. Then the specific parameters of alloy 2024 are commented. It is followed by short summary of aluminum inorganic chemistry and chemistry of its compounds. Next chapter is an introduction to corrosion and description of its particular forms. The following section sets out a summary of results of recent research in the field of aluminum alloys corrosion, some details about corrosion product analysis and published results concerning hypochlorites, what is the key substance in experimental part. The experimental part is focused on the influence of temperature and concentration of sodium hypochlorite solution on corrosion of Al 2024, cladded by pure aluminum.
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Age forming of aluminium alloys
Stanislav, Filip ; Petrásek, Miloslav (referee) ; Klement, Josef (advisor)
The diploma thesis is focused on the description and the verification of a relatively young creep age forming method. This method is based on a relaxation of stress and a creep of material, which occur by forming a part in the clamping tool during the artificial precipitation heat treatment at elevated temperature. After removing from the tool, the spring back and the residual stresses in the part are smaller compared to the conventional forming methods. This is mainly reflected in the increased fatigue resistance of the structure. The creep aging is only applicable to the precipitation heat treatable alloys. This thesis is focused on aluminium alloys, which are typical for the aerospace industry. The first part of the thesis describes principles of technology, its use in the aviation and material processes in the aluminium precipitation heat treatable alloys during the creep age forming. In the second part, there is a methodology of the verification of technology on samples made of the aluminium alloys ČSN EN AL-P 7075 and ČSN 424203 (approximate equivalent of ČSN EN AL-P 2024). Furthermore, a forming tool is designed, and experiments are performed according to the proposed methodology. At the end of the thesis, the experiments are evaluated and changes in the spring back of the samples are compared for three different methods of forming: the conventional cold clamping forming, the creep age forming and the creep age forming with an overaging.
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The corrosion study of part aircraft at the site of spot welds in the salt spray environment
Němčíková, Eva ; Doležal, Pavel (referee) ; Pacal, Bohumil (advisor)
This bachelor’s thesis is focused on the corrosion study of part aircraft at the site of spot welds in the salt spray environment. The panel is made of sheet of aluminium alloy AlCu4Mg1, with surface coated with aluminium of purity 99,5 %, and of square shapes of alloy AlCu4Mg1, without coating. Square shapes are an angle cleat. The thesis deals with corrosion characteristics at the site of spot welds and in the area of contact between them. It deals with character of corrosion, frequency of occurrence and range of corrosive attack. From the data files were detected critical places of construction.
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Measurement of corrosion resistance of anodized aluminum protective surface layers
Redr, Martin ; Jandová, Kristýna (referee) ; Chladil, Ladislav (advisor)
This master’s thesis is focused on anodic oxidation of an aluminium surface with subsequent sealing of the surface using mid-temperature sealing methods. The research in the theoretical part of the thesis is carried out in surface treatments of aluminium and its alloys, where attention is mainly paid to anodic oxidation, as it is the most widely used surface treatment. The second discussed and at the same time key topic is the sealing process of the anodic coating, which has a fundamental effect on the quality of the corrosion resistance of the resulting surface. In the practical part of the thesis, a number of anodic oxidation experiments with subsequent sealing of the coating on prepared aluminium samples and their subsequent evaluation according to ČSN EN ISO 3210 standard were carried out. Mid-temperature sealing experiments were mainly focused on the use of triethanolamine (TEA), which seems very promising in terms of the resulting sealing quality.
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Fatigue properties of EN-AW 7020 aluminium alloy
Kuběna, Martin ; Němec, Karel (referee) ; Věchet, Stanislav (advisor)
This bachelor thesis focuses on the fatigue properties of wrought aluminum alloy EN-AW 7020. The theoretical part deals with the properties and use of aluminum alloys and metal response to cyclic loading. The experimental section is concerned with the structure of alloy EN-AW 7020 and its mechanical properties, especially fatigue characteristics. The goal is to construct S-N curves in the high- and low-cycle region and determine the fatigue endurance limit at 10^8 cycles.
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ELECTRON BEAM WELDING OF HETEROGENEOUS WELDS OF Ti/Al ALLOYS
Havlík, Petr ; Dřímal, Daniel (referee) ; Schwarz,, Drahomír (referee) ; Foret, Rudolf (advisor)
The problematics of weldability of heterogeneous welds of aluminium and titanium alloys produced by electron beam welding is discussed in this work. Homogenous welds of selected alloys were analyzed in the first stage. Welding of these materials relates to formation of intermetallic phases at the interface of base materials due to differences in physical, chemical and metallurgical properties of base materials. One of the prerequisites for producing high quality weld joints is to find optimal process parameters. The influence of selected process parameters to integrity, structure and mechanical properties of heterogeneous Al/Ti joints is evaluated.
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