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Review of In-situ and Ex-situ Techniques for Characterization of Li-ion Batteries
Klvač, Ondřej ; Kazda, Tomáš
This paper describes the analytical techniques andsample preparation methods used in in-situ and ex-situ investigationsof Li-ion batteries (LIBs). The introduction briefly describesthe current state of Li-ion batteries and their aging mechanisms.The article is further divided into a description of ex-situ and insitutechniques. Ex-situ techniques include a detailed descriptionof sample preparation for repeatable results using Broad IonBeam (BIB) polisher. In-situ techniques are described in theform of a report of selected published experiments. The paper isfurther extended with our experiments involving ex-situ analysesof cylindrical and flat cell types using BIB in planar modeand cross-section mode. In the case of in-situ experiments, thedesign of the cell inside the SEM chamber is described. Twoexperiments have been performed - on the surface of a MEMSchip, and also using a micromanipulator as a current collectorof the investigated electrode.
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Increasing the productivity of the design process
Chaloupka, Michal ; Knoflíček, Radek (referee) ; Marek, Jiří (advisor)
This thesis focuses on the topic of increasing the productivity of the design process in a competitive environment. The thesis consists of two parts. The first part is devoted to the explanation of the methodological approach, which is called the Brno Design School, which is based on a systemic approach standing on three key pillars, which are defined in the theoretical conception. The second part of the thesis is devoted to the proposal of a new methodology in the design process, which is presented on a specific example of a CNC machine tool. In the methodology, technical and economic criteria are proposed by means of which the different design options are evaluated. The aim of the methodology is to bring simplicity to the design process, thereby achieving savings in time, financial resources, and competitive advantage.
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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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Optimization of surface pretreatment of steel and aluminum alloy for subsequent application of powder paint
Běloch, Martin ; Březina, Matěj (referee) ; Wasserbauer, Jaromír (advisor)
This diploma thesis deals with various procedures of surface pretreatment of steel and aluminum alloy for subsequent application of powder coating substance. The work begins with an overview of the general characteristics of the materials used. The core part of the work is then a summary of the individual methods of pretreatment that can be used to modify the material surface. A special chapter is devoted to methodologies for the application of powder substances. Before separate application, the sample must first be carefully pretreated to ensure removal of organic compounds (e.g. oils from primary processing - grinding, cutting), or dust impurities to ensure the correct barrier effect. After dividing the individual methods of surface preparation, a powder paint system with a total thickness of approximately 50 µm is applied to the test material. Samples with different surface pretreatments will be compared both in terms of mechanical properties and in terms of electrochemical properties.
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Correlative tomography
Vařeka, Karel ; Touš,, Jan (referee) ; Bábor, Petr (advisor)
Předložená diplomová práce se zabývá korelativním přístupem multimodální analýzy struktur prokovování s různým rozlišením. Výzkum je součástí mezinárodního projektu týkajícího se charakterizace poruch zmíněných struktur, které jsou implementovány v polovodičových zařízeních. Kombinace korelativní mikroskopie a tomografie technikami NanoXCT, FIB-SEM (EDS), FIB-SIMS a AFM byla navržena k zavedení opakovatelného pracovního postupu. Tomografie fokusovaným iontovým svazkem je metoda přesného odprašování v řezech, která mimo jiné v každém průřezu získává cenné snímky s vysokým rozlišením (FIB-SEM) nebo mapy chemického složení (FIB-SIMS). Následující transformace obrazu umožňuje identifikaci defektů jako funkci hloubky ve struktuře. Práce dále věnuje pozornost metodám sjednocení obrazů za účelem optimální prezentace získaných dat.
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Study of the microstructure of deposited Ni-P coatings with different phosphorus contents
Najser, Tomáš ; Kosár, Petr (referee) ; Wasserbauer, Jaromír (advisor)
The aim of this bachelor thesis was the preparation and characterization of Ni-P coatings with different phosphorus contents on the substrate of AZ91 magnesium alloy. The theoretical part deals with magnesium alloys and specifies the utilized substrate AZ91. It also focuses on Ni-P coatings, their microstructure and their properties. However, there are also described factors affecting the rate of deposition and the resulting behavior of these coatings. Last but not least, the theoretical part summarizes the basic principles of laboratory methods used in the experimental part for observation and characterization of samples. Conclusion of the theoretical part consists of several background researches where the authors deal with similar problems and factors influencing the resulting behavior of Ni-P coatings. The experimental part is focused on the deposition of each Ni-P coatings on the AZ91 alloy and their characterization. The study of deposited Ni-P layers was focused on the determination of their microstructural texture by XRD method, mechanical properties and elemental composition depending on phosphorus content.
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