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Influence of fuel additives for passenger cars
Obytová, Eliška ; Bradáč, Albert (referee) ; Bilík, Martin (advisor)
This diploma thesis deals with the addition of automotive fuels and their effects. The aim was to evaluate the function and efficiency of fuel additives present in the fuel at gas stations, and subsequently to improve the fuels accordingly by adding additional individual chemical compounds. The theoretical part explains the concepts, functions and processes related to fuel additives and the basics of tribotechnology. The practical part deals with the process of testing the properties of fuels, their functions, additional additives and its impact for practical use.
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Nanolubricants for practical applications
Sochor, Ondřej ; Frýza, Josef (referee) ; Svoboda, Petr (advisor)
This bachelor thesis is concerned with describing nanolubricants and enhancing their characteristics using suitable additives, such as nanoparticles. These can improve their tribological properties and reduce mechanical wear and friction between two surfaces. This thesis summarizes manufacturing, some features and mechanisms that apply to nanoparticles and nanolubricants. The main outcome of the work is a synthesis of acquired knowledge in the field of nanolubricants for the purpose of practical application and description of current trends in its research as being used as additives.
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Analysis and Evaluation of Surface Texture Effects of Tested Samples
Fuciman, Lukáš ; Dobrocký, David (referee) ; Sedlák, Josef (advisor)
The thesis deals with an evaluation of the surface texture of various materials, created by machining technologies (turning, milling and grinding). As for the theoretical part of the thesis, it contains a theoretical analysis of the effect of surface texture on friction, wear, coating and lubricating properties. The main emphasis is put on the analysis of the most frequently evaluated profile and surface parameters as well as their possible influence on the functional areas of machined parts. The experimental part includes evaluated and compared measured data based on the monitored parameters with benefits for machinery industry.
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The effect of proteins on friction of artificial articular cartilage
Plachý, Tomáš ; Nečas, David (referee) ; Rebenda, David (advisor)
This bachelor thesis deals with the influence of the composition of synovial fluid on the coefficient of friction of artificial cartilage. The effect of protein concentration and their combination with other components of synovial fluid on the coefficient of friction of CD hydrogels simulating artificial cartilage is observed. All experiments were performed at a constant load of 10 N, speed 10 mm / s, temperature 37 ° C. In experiments investigating the effect of a combination of hyaluronic acid and phospholipids together with proteins, concentrations corresponding to a healthy individual were used. In experiments where the effect of the proteins themselves and their own combinations was investigated, concentrations corresponding to both a healthy individual and patients with advanced osteoarthritis or patients with aseptic release of the prosthesis were used. The work shows that when using the proteins alone, or their combination, there is a decrease in concentration of friction coefficient with increasing concentration. However, if hyaluronic acid alone or phospholipids alone is added to the protein, the coefficient of friction increases. The reduction occurs only after the addition of the combination of acid and phospholipid.
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Evaluation of lubricants for forming
Svobodová, Hana ; Podaný, Kamil (referee) ; Lidmila, Zdeněk (advisor)
The aim of this diploma thesis is experimental testing and evaluation of the suitability of lubricants for drawing stainless chromium - nickel austenitic steel X5CrNi18-10 and comparison of the results obtained from the work [51]. The testing was performed by modeling the friction between the traction edge and the retainer, which corresponds to the real production process at ACO Industries. The introductory part of the thesis describes the process of deep drawing, followed by a description of tribology and the effect of friction. The individual types and properties of lubricants are described in more detail. The main part of the work deals with the testing of lubricants. The results are then described and evaluated.
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Innovation of guide rail production technology
Zlínská, Marie ; Ohnišťová, Petra (referee) ; Píška, Miroslav (advisor)
This bachelor's thesis provides the new plan of technological process of production of the guide rail used on the splitting machine type SVIT 06155. The current process of component production, which was designed more than 40 years ago, is proving inefficient with regard to current production possibilities. The first part of the work describes the process of splitting the leather, further explains the principle of operation of the machine and then defines the required properties of the guide rail in terms of operating conditions. The analysis of the issue reveals two possible solutions. The first is a change of the material of the guide rail and the second is a change of the coating technology and its composition. The introduction of the experimental part presents the solution, together with the newly designed production process and drawing documentation of the guide rail. The correctness of the design is further verified by the production of the component itself and by the evaluation of the surface condition of the Alicona device using the surface and profile method. Finally, an evaluation is made and recommendations for future production of the component are discussed.
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Untersuchung von Strukturen und Beschichtungen für tribologisch optimierte Umformwerkzeugoberflächen für die Aluminiumfeinblechbearbeitung
Kořenek, Jakub ; Hänel, Thomas (referee) ; Blecha, Petr (advisor)
V rámci bakalářské práce je provedena rešerše ke stavu techniky z pohledu tribologie, tváření hliníku, povlakování, strukturování a v závěru rozdělení tribologických zkoušek a metod jejich hodnocení. V praktické části jsou vyhodnoceny už dříve provedené pokusy na oscilačním tribometru. Následně byly provedeny pokusy tažení pásu s ohybem a bez ohybu s různými parametry pro jednotlivé zkoušky. Testovány byly různé laserové struktury (křížové, liniové, bodové) s variací jejich hloubky a pokrytí vzorků. V závěru práce jsou výsledky pokusů zhodnoceny z pohledu opotřebení, koeficientu tření a stability tribologického systému v průběhu pokusu. Z výsledků vychází doporučení pro následující pokusy a možné oblasti aplikace jednotlivých struktur.
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Improving friction of lubricated contacts by modifying thermal conductivity
Šnevajs, Matěj ; Hartl, Martin (referee) ; Šperka, Petr (advisor)
This thesis deals with an experimental study regarding the effects of the thermal conductivity of contact bodies on the friction, lubricant film thickness and temperature distribution in EHL contact. The thesis focuses on the configuration of the ball on disc contact. The contact body materials are characterized by a wide range of thermal properties. New contact pairs are proposed and used in the study in order to make the contact bodies’ thermal properties dependent on the behaviour of EHL contact. The colorimetric interferometry method is used to measure the lubricant film thickness and the infrared thermography method is used to observe the temperature distribution in EHL contact. The author presents the assumed mechanism of heat transfer within EHL contact on the basis of different heat transfer mechanisms. The same conditions – such as the Hertz pressure, mean entrainment speed, sliding speed and ambient temperature – are induced for all the contact pair combinations. That is why the differences in the results are attributed to the different thermal phenomena in the contact, caused by the thermal properties of the contact bodies. In the case of contact bodies with a reduced heat dissipation capability, a reduction of the friction coefficient of up to 50 % is observed, which is attributed to an increase in the lubricant temperature, resulting in a decrease in its viscosity. This is confirmed by the infrared thermography method, whereby a significantly higher lubricant temperature is observed in the case of a combination of contact materials with a lower heat dissipation capability.
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Multiphase Ti-Ni layer on Ti6Al4V substrate by local nickel alloying
Barančíková, Miriama ; Havlík, Petr (referee) ; Jan, Vít (advisor)
This bachelor's thesis comprises two main parts. The first part consists of a theoretical study on the Ti6Al4V alpha-beta titanium alloy and on the possibilities of adjusting its tribological properties. The second part deals with experimental work with the aim of improving tribological properties of Ti6Al4V by alloying nickel into its surface, creating a hard and homogeneous surface layer with superior tribological properties. In order to achieve these goals, a nickel layer was created on a Ti6Al4V substrate by electrical deposition. The layer was later melted with an electron beam, thus creating a Ti-Ni alloy. Several different parameters of the electron beam were used to create a homogeneous surface layer. This layer was then tested for its mechanical properties. The evaluation of its microstructure was conducted as well. The experiment resulted in the creation of a surface layer with hardness and tribological properties superior to the base material.
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Analysis of contaminants in wheel and rail contact
Straka, Tomáš ; Galas, Radovan (referee) ; Kvarda, Daniel (advisor)
Wheel/rail contact is significantly influenced by so called third body – contaminants. Aim of this bachelor’s thesis is to analyse those contaminants in the contact and to create a brief overview. Short introduction into problem of wheel/rail contact is included, followed by description of main contaminants occurring in the contact. This thesis may be used as introduction into contamination of wheel/rail contact problem.
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