Investigation into the cause of spontaneous emulsification of a free steel droplet : validation of the chemical exchange pathway

Small Fe-based droplets have been heated to a molten phase suspended within a slag medium to replicate a partial environment within the basic oxygen furnace (BOF). The confocal scanning laser microscope (CSLM) has been used as a heating platform to interrogate the effect of impurities and their transfer across the metal/slag interface, on the emulsification of the droplet into the slag medium. The samples were then examined through X-ray computer tomography (XCT) giving the mapping of emulsion dispersion in 3D space, calculating the changing of interfacial area between the two materials, and changes of material volume due to material transfer between metal and slag. Null experiments to rule out thermal gradients being the cause of emulsification have been conducted as well as replication of the previously reported study by Assis et al.[1] which has given insights into the mechanism of emulsification. Finally chemical analysis was conducted to discover the transfer of oxygen to be the cause of emulsification, leading to a new study of a system with undergoing oxygen equilibration

Thermodynamic Assessment of the CaO–Al2O3–SiO2 System

The CaO–Al2O3–SiO2 system has been assessed with the CALPHAD technique, based on recent assessments of its binary systems. A new species AlO2−1 was introduced for modeling liquid Al2O3. The ternary liquid phase was described using the ionic two-sublattice model as. The available experimental data were critically examined, and a self-consistent set of thermodynamic descriptions was obtained. Various phase diagrams and property diagrams, including isothermal sections, isoactivity lines, and a projection of the liquidus surface, are presented. Information on viscosity seems to support the use of the AlO2−1 species

FMR study of surface‐tension‐related stress effects in ultraclean Ni thin films

Ni thin films, 19-837 .ANG. thick, were deposited under ultrahigh vacuum conditions (10-9 to 10-10 torr) onto extremely well degassed substrates. Intrinsic isotropic stress values in the films were detd. by ferromagnetic resonance; these measurements were carried out while the films were in the vacuum system in which they had been prepd. Films deposited onto substrates at 25-35 Deg were in a state of compressive stress when measured in UHV (ultrahigh vacuum). The surface tension provides an explanation for these stresses; the stress levels obey a simple model. After adsorption of O, N2O, or air, the stress levels in the films dropped to very low values, while adsorption of H, H2O, CO, and pyridine resulted in slightly smaller effects. Admission of N to the films caused no stress release. A small degree of reversibility of the latter effect was found for H and H2O. Adsorption of gases had a marked effect on the ferromagnetic resonance linewidths. Films thinner than 100 .ANG. showed deviations from the surface-tension model and the possible discontinuity of such films is indicated as the reason. Expts. on annealed films and expts. with films deposited onto substrates at elevated temps. were performed. The influence of vacuum conditions other than UHV during film deposition was investigated. The relevance of this study to the soln. of the problems of stress-corrosion cracking and H embrittlement is pointed out