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1	On microstructure formation and mechanical properties in grey cast iron / Diószegi, Attila, January 2004 (has links) (PDF) Diss. (sammanfattning) Linköping : Univ., 2004. / Härtill 10 uppsatser. Metallografi. Gjutning.
2	Machine Learning Methods for Segmentation of Complex Metal Microstructure Features Fredriksson, Daniel January 2022 (has links) Machine learning is a growing topic with possibilities that seems endless with growing areas of applications. The field of metallography today is highly dependent on the operators’ knowledge and technical equipment to perform segmentation and analysis of the microstructure. Having expert dependents is both costly and very time-consuming. Some automatic segmentation is possible using SEM but not for all materials and only having to depend on one machine will create a bottleneck. In this thesis, a traditional supervised machine learning model has been built with a Random Forest (RF) classifier. The model performs automatic segmentation of complex microstructure features from images taken using light optical- and scanning electron microscopes. Two types of material, High-Strength-Low-Alloy (HSLA) steel with in-grain carbides and grain boundary carbides, and nitrocarburized steel with different amounts of porosity were analyzed in this work. Using a bank of feature extractors together with labeled ground truth data one model for each material was trained and used for the segmentation of new data. The model trained for the HSLA steel was able to effectively segment and analyze the carbides with a small amount of training. The model could separate the two types of carbides which is not possible with traditional thresholding. However, the model trained on nitrocarburized steel showcased difficulties in detecting the porosity. The result was however improved with a different approach to the labeling. The result implies that further development can be made to improve the model. / Maskininlärning är ett växande område där möjligheterna verkar oändliga med växande applikationsområden. Området för metallografi är idag till stor utsträckning beroende av operatörens kunskap och de tekniska instrumenten som finns tillgängliga för att genomföra segmentering och analys av mikrostrukturen. Viss automatisk segmentering är möjlig genom att använda SEM, men det är inte möjligt för alla material samt att behöva vara beroende av endast en maskin kommer skapa en flaskhals. I denna uppsats har en traditionell övervakad maskininlärnings modell skapats med en Random Forest klassificerare. Modellen genomför automatisk segmentering av komplexa mikrostrukturer på bilder från både ljusoptiskt- och svepelektron-mikroskop. Två olika typer av material, Hög-Styrka-Låg-Legerat (HSLA) stål med karbider och korngräns karbider, samt nitrokarburerat stål med varierande mängd porositet analyserades i detta arbete. Genom användningen av en särdragsextraktions bank tillsammans med annoterad grundsannings data tränades en modell för vartdera materialet och användes för segmentering av ny bild data. Modellen som tränades för HSLA stålet kunde effektivt segmentera och analysera karbiderna med en liten mängd träning. Modellen kunde separera de två typerna av karbider vilket inte varit möjligt med traditionellt tröskelvärde. Den modell som tränades för det nitrokarburerade stålet visade emellertid upp svårigheter i att detektera porositeten. Resultatet kunde dock förbättras genom ett annorlunda tillvägagångssätt för annoteringen. Resultatet vittnar om att vidareutveckling kan göras för att förbättra slutresultatet. Machine learning Metallography Automatic segmentation Complex microstructures Random Forest classifier. Maskininlärning Metallografi Automatisk segmentering Komplex mikrostruktur Random Forest klassificerare Other Materials Engineering Annan materialteknik
3	Karaktärisering av stålplåt : Metallografi och kemisk analys / Characterization of steel sheet : Metallography and chemical analysis Petersson, Rickard, Nilsson, Rebecca January 2017 (has links) Studien har genomförts på ett antal stålplåtar från olika kulturhistoriska byggnader. När kulturhistoriskt värdefulla byggnader ska renoveras måste detta göras med så god kunskap som möjligt om byggnadens olika delar och de värden dessa representerar. Det problem som studien har ämnat att lösa har varit en bristande kunskap om historiska stålplåtar. Studien har därför utförts för att bidra med kunskap som kan användas när gamla byggnader ska renoveras.För att uppnå syftet att bidra med kunskap som kan vägleda renovering av kulturhistoriska byggnader har studiens mål varit att undersöka hur de olika plåtarna tillverkats och vilka resultat de processerna har fått.Detta har genomförts genom att utföra en metallografi på samtliga prover för att undersöka deras mikrostrukturer och få en förståelse för materialen. Även en kemisk analys av materialens innehåll har gjorts genom en optisk emissions spektroskopi.De resultat som hämtades från plåtarna visade hur stor skillnad det var mellan olika tillverkningsmetoder och deras konsekvenser. Genom att ha sett den mångfald av egenskaper som fanns bland plåtarna har slutsatserna dragits att det finns ett värde i att respektera de äldre materialen.Genom att vara medveten om att det kan finnas stora skillnader i materialen kan valet av plåt göras på ett bättre sätt. Under studiens gång blev det även uppenbart hur mycket historia som fanns lagrad i de gamla plåtarna som är viktig att ta vara på. / The study has been conducted on a number of steel plates from different buildings of cultural and historical value. When old, cultural buildings are to be renovated, it must be done with as much knowledge as possible about the different parts of the building and the values that they represent. The problem that the study has aimed to solve has been an inadequate level of knowledge in regards to historical steel plates. Because of this, the study has been conducted to contribute with knowledge that could be used when old buildings are to be renovated.To achieve the purpose of contributing knowledge to guide renovations of culturally and historically valuable buildings, the goal of the study has been to analyze how the different plates have been made and what the results of those processes were.This has been carried out by conducting a metallography on all of the samples to analyze their microstructures and to gain an understanding of the materials. A chemical analysis has also been conducted on the contents of the materials by using optical emission spectroscopy.The results showed how big of a difference there was between different manufacturing methods and their consequences. By discovering the diversity of the properties of the plates the conclusion has been drawn that there is value in respecting the values of the older materials.By being conscious of how large the difference is between different types of steel sheets, better decisions can be made during choice of steel sheet, and it is more obvious how much history that is stored within the old plates. forging hot-rolling cold-rolling historic "steel sheet roofing" "roof sheet" microstructure metallography oes spectroscopy smide varmvalsning kallvalsning historiska plåttak takplåtar mikrostruktur metallografi oes spektroskopi Metallurgy and Metallic Materials Metallurgi och metalliska material
4	Testing and evaluation of component made using electron beam melting and Alloy 718 powder Nilsson, Erik, Johansson, Daniel January 2017 (has links) The aerospace industry is constantly striving to becoming more economical and environmentally friendly. One of many efforts to achieve this is the Lightcam project which in this case is evaluating the use of additive manufacturing in the form of electron beam melting in conjunction with the nickel-based superalloy, Alloy 718. This combination is not fully explored and examined. For this purpose, a demonstrator vane was produced and it was subsequently evaluated in this thesis. The evaluation was performed in as-built condition and was divided in non-destructive testing, evaluation of these methods and metallographic review to confirm the results, and potentially revealing more properties. The non-destructive testing was performed using conventional radiography and computed tomography. Both methods struggled to deliver complete and reliable results, for varying reasons. Radiography could deliver results of the whole vane, but these were impossible to evaluate due to the rough surface created by the electron beam melting process. The computed tomography on the other hand was not affected by the rough surface and produced usable, though not complete, results of the vane. The reason for the computed tomography’s inability to deliver complete results was the material, varying thickness and complex geometry of the vane. As a complement and to verify the results from the non-destructive testing, a metallographic examination was conducted. These tests were conducted with the aim of answering the following three questions: What non-destructive testing methods are suitable to evaluate Alloy 718 components manufactured with electron beam melting? - Neither radiography nor computed tomography are suitable as a sole evaluation method, for various reasons. All surface dependent methods were deemed unsuitable without testing due to the rough surface. What types of defects and in what quantity can they be found in the produced vane? - Defects found are: Porosity and lack of fusion, both found as internal and partially external and in varying sizes. Where are the defects located? - Pores are mainly found in the center of sections modeled to a 3mm thickness. Lack of fusion was found between build layers in all thicknesses. Apart from these results, hardness was found to vary depending on build height, increasing from the bottom towards the top. Microstructure was also found to vary with the build height, but always consisting of either equiaxed or columnar grains. / Lightcam Additive Manufacturing AM Electron Beam Melting EBM Alloy 718 Inconel 718 Inco 718 Non-Destructive Testing NDT Radiography Computed Tomography CT Metallography Additiv tillverkning Oförstörande provning Datortomografi Röntgen Metallografi Aerospace Engineering Rymd- och flygteknik
5	To Make Iron of Iron : A Comprehensive Analytical Study of Spade Shaped Iron Bars Pappas Adlerburg, Nickolas T. January 2017 (has links) This thesis aims to provide adequate analytical information on the spade shaped iron bars of Norrland and central Sweden. While their significance has been thoroughly debated for decades, analytical research on them has been confined to cases of single artefacts or theoretical interpretations of their value, meaning and origin. In this study a comprehensive approach is taken into consideration. Based on X-Ray fluorescence (XRF), scanning electron microscopy (SEM) and metallographical analysis this thesis seeks to facilitate new interpretations on quality, production centres and usage based on analytical results. Aiming to settle some of the long lasting questions regarding the artefacts while producing results which can further the discussion by raising new questions, previously unasked. Archaeological Science Scandinavian Iron Age Nordic Iron Age Spade Shaped Iron Bars Norrland Iron Bars Archaeometallurgy XRF SEM/EDS Metallography Vendel Era Migration Period Roman Iron Age Nickel Cobalt Limonite Iron Ores Helgö Uppland Gästrikland Medelpad Hälsingland Jämtland Laborativ arkeologi Nordisk järnålder Spadformiga ämnesjärn Norrland Ämnesjärn Arkeometallurgi XRF SEM/EDS Metallografi Vendeltid Folkvandringstid Romersk Järnålder Helgö Nickel Cobalt Myrmalm Bergmalm Uppland Gästrikland Medelpad Hälsingland Jämtland Archaeology Arkeologi
6	To Make Iron of Iron : A Comprehensive Analytical Study of Spade Shaped Iron Bars Pappas Adlreburg, Nickolas January 2017 (has links) This thesis aims to provide adequate analytical information on the spade shaped iron bars of Norrland and central Sweden. While their significance has been thoroughly debated for decades, analytical research on them has been confined to cases of single artefacts or theoretical interpretations of their value, meaning and origin. In this study a comprehensive approach is taken into consideration. Based on X-Ray fluorescence (XRF), scanning electron microscopy (SEM) and metallographical analysis this thesis seeks to facilitate new interpretations on quality, production centres and usage based on analytical results. Aiming to settle some of the long lasting questions regarding the artefacts while producing results which can further the discussion by raising new questions, previously unasked. Archaeological Science Archaeometallurgy Spade Shaped Iron Bars X-Ray Fluorescence (XRF) Scanning Electron Microscopy (SEM) Metallography Swedish Archaeology Archaeology in Norrland Scandinavian Iron Age Nordic Iron Age Roman Iron Age Migration Period Vendel Period Prehistoric Metallurgy Slag Iron Bar Currency Bar Bloomery Bloom Iron Bog Iron Limonite Mineral Iron Ores Hematite Magnetite Phosphoric Iron/Steel Prehistoric Steel Ferrite Pearlite Nickel Cobalt Phosphorus Arsenic Magnesium Sulfur Manganese Norrland Middle Norrland Uppland Gästrikland Hälsingland Medelpad Jämtland Södermanland Helgö Torsåker Gåcksätter Alborga Offerdal Selånger Villberga Arbrå Laborativ Arkeologi Arkeometallurgi Spadformiga Ämnesjärn Röntgenfluorescens (XRF) Svepelektronmikroskop (SEM) Metallografi Svensk Arkeologi Norrländsk Arkeologi Förnnordisk Arkeologi Skandinavisk Järnålder Nordisk Järnålder Fornnordisk Järnålder Romersk Järnålder Folkvandringstiden Vendeltiden Forhistorisk Metallurgi Slaget Ämnesjärn Blästerugn Blästa Myrmalm Sjömalm Limonit Bergmalm Hematit Magnetit Fosforisk Järn/Stål Förhistorisk Stål Ferrit Pearlit Nickel Kobolt Fosfor Arsen Magnesium Svavel Mangan Norrland Mellannorrland Uppland Gästrikland Hälsingland Medelpad Jämtland Södermanland Helgö Torsåker Gåcksätter Alborga Offerdal Selånger Villberga Arbrå Archaeology Arkeologi

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