1. Microstructural, corrosion and mechanical properties of a WE43 alloy : conventional extrusion versus SPDAnna Dobkowska, Aleksandra Zielińska, Irena Paulin, Črtomir Donik, Milena Koralnik, Bogusława Adamczyk-Cieślak, Monika Wieczorek-Czarnocka, Dariusz Kuc, Jiří Kubásek, Tomasz Mikuszewski, Matjaž Godec, Jarosław Mizera, 2024, original scientific article Abstract: A hexagonal close-packed-structure WE43 alloy was extruded without any preheating of the initial billet using extrusion with an oscillating die to improve the corrosion and mechanical properties. The WE43 alloy was extruded at high ratios of R 1 5:1, R 2 7:1 and R 3 10:1. Electron back-scatter diffraction and transmission electron microscopy were used to determine the microstructural properties of the alloys. The influence of the extrusion method and the extrusion ratios on the corrosion and mechanical properties were investigated. Electrochemical tests were performed, and the corrosion damage was inspected. Tensile tests were made using micro specimens. When compared to conventional extrusion, the microstructural changes obtained with the KoBo method at R 5:1 increased the corrosion resistance, which was not only due to the grain refinement, but also due to the intensity of the texture. A decline in the corrosion resistance of the alloys deformed at higher extrusion ratios was observed. This was a result of the massive plastic strain imposed by the KoBo die. The room-temperature mechanical properties of the KoBo-extruded alloys were improved. However, at higher temperatures the mechanical properties decreased due to the solutioning of tiny triple precipitates.
Keywords: WE43, several plastic deformation, microstructure, corrosion, mechanical properties
Published in DiRROS: 23.07.2024; Views: 96; Downloads: 32
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2. Three-dimensional MRI evaluation of the effect of bladder volume on prostate translocation and distortionŽiga Snoj, Andrew B. Gill, Leonardo Rundo, Nikola Sushentsev, Tristan Barrett, 2020, original scientific article Keywords: prostate translocation, prostate distortion, gland deformation, bladder volume, magnetic resonance imaging, radiation therapy planning
Published in DiRROS: 12.07.2024; Views: 93; Downloads: 46
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3. Microstructure and properties of an AZ61 alloy after extrusion with a forward-backward oscillating die without preheating of the initial billetAnna Dobkowska, Aleksandra Zielińska, Irena Paulin, Črtomir Donik, Maciej Łojkowski, Milena Koralnik, Bogusława Adamczyk-Cieślak, Krystian Paradowski, Marek Tkocz, Dariusz Kuc, Jiří Kubásek, Matjaž Godec, Wojciech Święszkowski, 2023, original scientific article Keywords: magnesium alloys, severe plastic deformation, microstructure, mechanical properties, corrosion, extrusion, high deformation ratio
Published in DiRROS: 17.05.2024; Views: 251; Downloads: 168
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4. The deformation of alkali-activated materials at an early age under different curing conditionsMark Češnovar, Katja Traven, Vilma Ducman, 2021, original scientific article Abstract: The production of alkali-activated materials (AAMs) is known for its environmentally friendly processing method, where several amorphous-rich aluminosilicate material sources combine with an alkali media solution to form solid, ceramic-like materials. In terms of the Si:Al, Na(K):Al, and Na(K):H2O ratios, the theory of AAM formation is quite well developed, but some open questions in the technology process remain, especially with regards to the means of curing, where the generation of defects can be persistent. Knowing that deformation is extremely high in the early ages, this study investigates the effects of temperature and moisture on shrinkage behavior within the first 72 h of AA pastes made from ladle (LS) and electric arc furnace (EAF) slag and activated by sodium silicate (Na2SiO3). The method to determine the deformation of alkali-activated slag-based materials, in terms of both autogenous and drying shrinkage, was based on the modified ASTM C1698-19 standard for the measurement of autogenous shrinkage in cement pastes. Autogenous deformation and strain were measured in four samples, using the standard procedure at room temperature, 40 and 60°C. Furthermore, using an adjusted method, nine samples were characterized for strain and partial surface pressure, while drying at room temperature, 40, or 60°C at a relative humidity of 30 or 90%. The results show that the highest rate of autogenous shrinkage occurred at a temperature of 60°C, followed by drying shrinkage at 60°C and 30% relative humidity, owing to the fact that the rate of evaporation was highest at this moisture content. The study aimed to provide guidance regarding selection of the optimal curing set in order to minimize deformations in slag-based alkali-activated materials. In the present case, curing at a temperature of around 40°C under lower moisture conditions for the first 24 h provided optimal mechanical properties for the slags investigated. The methodology might also be of use for other aluminosilicate sources such as metakaolin, fly ash, and mineral wool–based alkali-activated materials.
Keywords: alkali-activated materials, slag, drying, autogenous shrinkage, partial surface pressure, curing deformation
Published in DiRROS: 03.07.2023; Views: 552; Downloads: 242
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5. Thermal-deformation model of a SR-modified A356 aluminum alloyYongyue Liu, Xianglai Xu, Jiangxiong Cheng, Hongwei Sun, Xueping Ren, Peng Jiang, 2022, original scientific article Keywords: A356 aluminum alloy, Sr modification, microstructure, thermal-deformation model
Published in DiRROS: 22.06.2022; Views: 747; Downloads: 219
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