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Current principles of Cold Spray coating, Cu coating characteristics
Barinka, Michal ; Jan, Vít (referee) ; Řehořek, Lukáš (advisor)
This bachelor thesis deals with the current principles of coating with the Cold Spray method. The research part deals with the principle of layer formation using the Cold Spray method. Furthermore, the current state of this technology on the market and its application in practice is summarized. The structure of deposited copper layer on two different substrates is evaluated in the experimental part.
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Microstructure and properties of YSZ thermal barier coatings deposited onto CoNiCrAlY bond coats remelted by electron beam
Slavíková, Barbora ; Jan, Vít (referee) ; Dlouhý, Ivo (advisor)
The master thesis is dealing with characterization of the structure and properties of the YSZ thermal barrier coating deposited by water hybrid plasma spray technology on the CoNiCrAlY bond coats modified by using electron beam and vacuum annealing. Deposition of the bond coats was performed via high velocity oxy-fuel technology and cold spray. In case of experimental evaluation, the microstructure and chemical composition of the ceramic top coat deposited with powder and suspension feedstock was analyzed. The same analysis procedure was used also for bond coats after electron beam remelting by using two sets of parameters. Furthermore, the changes in microstructure and chemical composition of the remelted and annealed bond coats was evaluated. Eventually, the micromechanical properties of the top coats and the bond coats were measured. The ceramic top coats deposited with powder feedstock exhibited the structure composed by splats, while the top coats deposited in form of suspension showed fine structure with columnar grains. The dendritic structure was observed on remelted bond coats. The annealing process had an influence on the structure in form of coarsened phases and the chemical composition was changed due to diffusion of the elements.
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Determination of mechanical characteristics of coatings using impulse excitation technique
Valášek, Daniel ; Řehořek, Lukáš (referee) ; Válka, Libor (advisor)
This diploma thesis deals with the determination of the Young’s modulus of coatings using the impulse excitation technique (IET). The theoretical part of the thesis describes Cold and Thermal Spray technology, theoretical foundations of the impulse excitation technique and models of composite materials. The experimental part of the thesis deals with the determination of the tensile modulus of copper coating created by Cold Spray technology. The impulse excitation technique has been used to measure fifteen samples with coating thickness ranging approximately from 0,4 to 2 mm. Results from this measurement were evaluated using five composite models to establish the Young’s modulus of the applied coating. The best results were achieved by using the composite model based on rule of mixtures (ROM).
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Digital commissioning of robotized workplace for cold spraying of rotating parts
Šimůnek, Petr ; Bražina, Jakub (referee) ; Vetiška, Jan (advisor)
This work deals with the virtual and later real commissioning of the workplace for cold spraying of rotating parts, which is located in the laboratories of the Institute of Materials Science and Engineering, Faculty of Mechanical Engineering, Brno University of Technology. The workplace put into operation in this way serves the employees of the mentioned institute for experimental activities in the field of cold spraying. The theoretical part of the thesis describes all the essentials associated with virtual commissioning and the theory of cold spray. The practical part then deals with the creation of a robotic program, including the user interface, which is used to control the workplace. Part of this diploma thesis is also the realization of the connection between the external motor driver and the robot controller via the PROFINET communication bus.
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Cyclic plasticity and low-cycle fatigue resistance of materials prepared by the ColdSpray method
Brůža, Jaromír ; Šulák, Ivo (referee) ; Zapletal, Josef (advisor)
In the theoretical part, the diploma thesis focuses on Cold spray technology and parameters affecting the efficiency and quality of deposition. Next, there is an introduction to the fatigue process of materials. The theory is concluded with a summary of the current knowledge regarding materials created by Cold spray technology in the field of fatigue. In the practical part, volumetric bodies were created from the material EN AW7075. Specimens for tensile and fatigue tests were cut from the bodies by electrosparking. From the material and powder, metallographic cuttings were created for the determination of porosity using Archimedes’ principle, hardness according to Vickers and evaluation of EDS and EBSD analysis. The basic mechanical properties were determined from the tensile tests and the Wöhler-Basquin parameters were determined from the fatigue tests along with the life curve. Subsequently, a fractographic analysis of fracture surfaces using SEM took place.
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Deposition of MMC-type composite coatings on steel substrates using the Cold Spray method
Šesták, Stanislav ; Doubrava, Marek (referee) ; Řehořek, Lukáš (advisor)
The Cold Spray method is a modern coating method characterized by several interesting advantages and drawbacks. One of the most significant drawbacks is the difficult manufacturing of materials with limited ductility. This work is dedicated to this issue, and its main objective is the development of tribological coatings for high-temperature applications on steel substrates. Extensive research focused on the nature of the chosen deposition method and its specifics in the context of materials with limited ductility is provided and concluded by a set of methodical approaches of deposition, which are verified in the experimental part of this work. The experimental part focused on processing Ni-B4C and Ni-SiC composite coatings, in which the reinforcement particle volume fraction was chosen as 20 and 40 %. All coatings were deposited on 42CrMo4 steel substrates. The analysis of the coatings consisted of microstructure evaluation (using optical and electron microscopy) hardness testing and adhesion testing. The Ni-SiC coating consisting of 40 vol.% SiC particles showed the best properties; compared to other coatings it offered the highest microstructural quality and microhardness values. This coating was found suitable for the chosen application, and further suggestions on improving the quality of this coating were provided in this work’s conclusion.
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Cold spray technology as a tool for repairing of worn parts
Hevessy, Zoltán ; Heczko, Martin (referee) ; Doubrava, Marek (advisor)
Cold spray (CS), also known as cold dynamic gas spraying, is a state-of-the-art process from the thermal spray family, characterized by a combination of low temperature and high velocity of the particles, which makes coatings of sufficient quality for applications in many industries where other processes cannot be used, including repairs of civil and military aircraft and helicopters. The bachelor thesis presents a detailed description of this process, the influence of its parameters on the quality of the coatings, examples of repairs and evaluation of the mechanical and corrosion properties of the repaired parts.
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