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Oxide particles are considered to be one of the reasons for the stability of cellular porous Al foam. Thus, the contact angle (ө) of molten pure aluminum on oxide substrates, including Al2O3, CaO·2Al2O3 (CA2), CaO·6Al2O3 (CA6), mullite (3Al2O3·2SiO2), and SiO2 was measured in a vacuum heating microscope at a temperature of 950°C to determine the value of wettability of molten aluminum on various oxides. Thereafter, the measured contact angles followed the tendency as mullite (155°) > CA6 (152°) > MgAl2O4 (151°) > Al2O3 (149°) > SiO2 (124°) > CA2 (100°). Furthermore, the cross‐sectional area between molten aluminum and substrates was thoroughly analyzed, and the reaction products, such as the Al2O3 layer at the interface, have been detected. Thermo‐Calc, with the combination of available databases, was used to perform thermodynamic simulations and to discuss and predict possible reactions under the current experimental conditions. [ABSTRACT FROM AUTHOR]

The current investigation delves into the oxidation resistance of magnesia‐carbon‐bonded (MgO‐C) refractory enhanced with calcium magnesium aluminate (CMA) cement, metallic aluminum, and Carbores P across a broad temperature spectrum from 800 to 1600 °C. The results demonstrate that the modification with CMA up to a temperature threshold of 1200 °C does not compromise the material's inherent oxidation resistance. However, above this temperature, a decrement in oxidation resistance is observed. The impact of grain size variation in CMA on the oxidation resistance of MgO‐C refractories is notable, and the finer grains show a superior performance. MgO‐C sample with Carbores P has excellent oxidation resistance up to 1000 °C, while above 1200 °C, its oxidation resistance strongly deteriorates. The metallic aluminum addition exhibits a remarkable oxidation resistance throughout the evaluated temperature range, indicated by a slight oxidation. [ABSTRACT FROM AUTHOR]

Pure alumina (Al2O3) and carbon‐bonded alumina (Al2O3−C) are used to investigate their interaction with iron (Armco) at 1625 °C, applying the sessile drop method. The investigations are conducted inside a heating microscope for 1 h under argon atmosphere with low oxygen partial pressure. No whiskers formation is observed from the experiments with pure Al2O3 and molten iron. In the case of Al2O3−C/Fe system, several phenomena including the decarburization of Al2O3−C, Al2O3−C dissolution in molten iron, Al2O3 layer formation on the iron droplet, and Al2O3 whiskers formation are observed. To clarify the possible influence of iron on Al2O3 whiskers formation, blank Al2O3−C samples without the presence of iron are heated and held in a half‐sealed platinum crucible at 1550 °C for 2 h. Thereby, the Al2O3 whiskers formation is detected. Finally, the experimental investigations are supported with thermodynamic simulations. [ABSTRACT FROM AUTHOR]

Herein, a thermofluid–solid coupling model with erosion structure is established based on a blast furnace (BF) with a volume of 5500 m3. The temperature distribution of the hearth and the thickness of the solidified iron layer are studied under five hearth protection measures. It is found that the thickness of the solidified iron layer can be increased by the reduction of the production rate, closing the tuyere, increasing the taphole length, tapping through two opposite tapholes, and increasing cooling intensity. In particular, the reduction of the production rate is the most effective way to increase the thickness of solidified iron layer. In the case of the two tapholes that are near the erosion area for tapping, the solidified iron layer is found to be the thinnest. The validity of the model is verified by the thermocouple temperature of the hearth at different periods. [ABSTRACT FROM AUTHOR]