Research Data Repository of Saxon Universities
OPARA is the Open Access Repository and Archive for Research Data of Saxon Universities.
Researchers of Saxon Universities can either publish their research data on OPARA, or archive it here to comply with requirements of funding acencies and good scientic practice, without public access.
You can find the documentation of this service at the OPARA manual websites. If you need suppourt using OPARA please contact the Servicedesk of TU Dresden.
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Recent Submissions
Thermophysical Properties of Ladle Slag with Different SiO2 Content
(Technische Universität Bergakademie Freiberg, 2026-09-23) Yehorov, Anton; Volkova, Olena
The growing demand for electric vehicles, driven by global decarbonization policies, has led to an increase in the production of electric steel, which is characterized by a high silicon content. Producing this type of steel necessitates careful control of slag composition, particularly with high SiO2 content. This study investigates the thermophysical properties of cleanness slags with varying silicon oxide (SiO2) content, specifically examining viscosity, surface tension, and density. Silicon oxide, ranging from 1 to 20 wt%, was added to slags with a CaO/Al2O3 ratio of 1. The results show that increasing SiO2 content raises viscosity at temperatures above 1550 °C but reduces it at lower temperatures. Additionally, a linear decrease in density and surface tension was observed with increasing SiO2, which is attributed to the substitution of CaO with SiO2, thereby reducing the number of unsatisfied bonds in the slag network. Understanding these dynamics enhances control over slag-steel interactions in the steel ladle, ultimately improving process efficiency and steel quality.
GRK 2802: Interaction of Ladle Slag With Varying SiO2 Content and Recyclate-Based MgO–C Refractories
(Technische Universität Bergakademie Freiberg, 2026-09-23) Yehorov, Anton; Salpagarov, Eldar; Mospan, Anhelina; Stadtmüller, Till Manon Jannis; Schemmel, Thomas; Aneziris, Christos G.; Volkova, Olena
Industrial MgO–C refractories fabricated from either pure fuzed magnesia (R0) or 50 wt% recycled MgO–C (R50) were exposed to ladle slags (C/A = 1) with varying SiO2 content (1–20 wt%). Wetting and infiltration behaviors were investigated using the sessile drop method at 1600°C under an Ar atmosphere for different dwell times. Quenched slag–refractory interfaces were characterized by SEM-EDX and compared with phase equilibrium simulations using FactSage 8.1. Increasing SiO2 content at 1600°C reduced slag density and surface tension, increased viscosity, and shifted saturation from MgO to MgAl2O4 spinel. During heating, R50 samples exhibited more intense gas formation. This delayed wetting and significantly slowed the initial stage of slag infiltration. Upon contact with recycled-based refractories, the high-SiO2 slag formed a dense, 195 μm-thick MgAl2O4-rich layer, entrapping residual calcium-silicate slag and serving as an in situ protective barrier against further oxidation and corrosion. These results demonstrate that well-processed MgO–C recyclate can inhibit slag attack, first by delaying infiltration via transient gas release, and subsequently by promoting a protective spinel layer under suitable slag compositions. Furthermore, the findings highlight the influence of substrate carbon content and open porosity on the slag’s melting and infiltration behavior.
FOR3010: High-Temperature Compressive Behavior of Refractory Alumina–Niobium Composite Material
(Technische Universität Bergakademie Freiberg, 2026-09-23) Günay, Gökhan; Zienert, Tilo; Endler, Dirk; Aneziris, Christos G.; Biermann, Horst; Weidner, Anja
The development of coarse-grained refractory composites combining refractory ceramics with refractory metals provides new approaches for high-temperature applications. In particular, coarse-grained Nb-Al2O3 composites are widely interested due to their promising functional properties such as of high thermal shock resistance, low shrinkage and good electrical conductivity. In order to identify and release the potential of these materials in advanced applications, their mechanical behavior should be evaluated. This study presents room- and high-temperature compression behavior up to 1500 °C of Nb-Al2O3 refractory composites manufactured via castable and extrusion technology. The influences of production method, particle size, open porosity as well as temperature and strain rate are discussed. For comparison, pure niobium and alumina specimens are used as reference materials. The results indicate that Nb-Al2O3 refractory composites show high ductility at high temperatures. This behavior is also verified with microstructural investigations by scanning electron microscope (SEM).
FOR3010: Influence of particle size and fabrication method on mechanical properties of Nb-Al2O3 refractory composites under compressive loads at high temperatures
(Technische Universität Bergakademie Freiberg, 2026-09-23) Günay, Gökhan; Zienert, Tilo; Endler, Dirk; Aneziris, Christos G.; Biermann, Horst; Weidner, Anja
The present study explores the properties of both fine- and coarse-grained refractory composites made from niobium and alumina, designed for high performance applications at extreme temperatures, in abrasive environments, and under mechanical stresses. The effects of various production methods, including casting and extrusion, and different alumina particle sizes (fine or coarse) on the mechanical properties under compressive loads are investigated. Compression tests, as well as stress-relaxation and creep tests under compressive loads, are conducted at room temperature and high temperatures up to 1500 °C. The results are analysed concerning initial open porosities and particle sizes. The findings reveal that both particle size and manufacturing method significantly affect the mechanical properties of Nb-Al2O3 refractory composites. Additionally, the choice of production technique substantially influences the microstructure of the composites, leading to noticeable differences in mechanical performance. This research highlights the essential role of optimizing particle size and production methodologies to enhance the operational properties of Nb-Al2O3 refractory composites.
FOR3010: Characterization of high-temperature compressive behaviour of field-assisted sintered niobium-alumina refractory composites
(Technische Universität Bergakademie Freiberg, 2026-09-23) Günay, Gökhan; Kallien, Gregory; Kraft, Bastian; Wagner, Susanne; Schell, Karl Günter; Heilmaier, Martin; Biermann, Horst; Weidner, Anja
Nb-Al₂O₃ refractory composites have attracted significant attention due to their excellent performance at elevated temperatures. The incorporation of both metallic (Nb) and ceramic (Al₂O₃) phases enhances interest in these materials, i.e., the combination of the high toughness and plasticity of niobium with the refractoriness, high hardness, thermal stability, and oxidation resistance of alumina. In this study, the high-temperature mechanical behaviour of Nb-Al₂O₃ composites produced via field-assisted sintering (FAST) was investigated under compressive loading. Composites containing alumina particles of different sizes were subjected to compressive tests up to 1350 °C. The results were evaluated with respect to Nb content, alumina particle size, applied stress, and test temperature. Initial and post-mortem microstructural analyses were carried out to characterise the deformation behaviour. It was observed that an increase in the metal content led to an enhancement of plasticity, while changes in alumina particle size influenced the deformation behaviour.