Mineralogy of bloomery slags of the Shuvakish ironworks plant (outskirts of Yekaterinburg, Sverdlovsk oblast)

The mineralogy of slags of the Shuvakish ironworks plant is studied. The plant had been operated during the reign of Peter the Great from 1704 to 1716 years and was located within the present-day northwestern outskirts of Yekaterinburg. The slags are composed of fayalite aggregate with a signifcant content of hercynite and wustite and contain spherules of iron, glass, leucite and ferromerrillite. The chemical composition of rock-forming and ore minerals is determined on a JSM-6390LV (Jeol) SEM equipped with an INCA Energy 450 X-Max 80 EDS (Oxford Instruments) (Institute of Geology and Geochemistry UB RAS, Yekaterinburg). The slags formed as a result of bloomery iron production. Their formation temperature is estimated in a range of 1177 °С on the basis of eutectic crystallization of wustite and fayalite. The Shuvakish plant was supplied with marsh iron ore, which was most likely extracted in the nearest Moleben swamp located to the north from the plant.

IODP Hole 1473A (Atlantis Bank, SWIR) - Formation of felsic veins in gabbros: reactions at the contact between felsic melt and host rock

<p>Hole U1473 (32° 42.3622’ S; 57° 16.6880’ E), located on the summit of Atlantis Bank at the ultra-slow spreading Southwest Indian Ridge was drilled to 789.7 m below seafloor (mbsf) during IODP Expedition 360. It consists of massive gabbros cut by nearly 400 felsic veins, which are evolved, SiO<sub>2</sub>- enriched lithologies comprising ~1.5 vol% of the drill core. They vary in composition from diorite to trondhjemite. For their formation, 3 endmember models are discussed: (1) fractional crystallization; (2) hydrous anatexis of mafic rocks; (3) liquid immiscibility in an evolved MORB system.</p><p>Mineral assemblages in the felsic veins include mainly plagioclase, amphibole, Fe-Ti oxides ± quartz and minor zircon, apatite, ± titanite, ± biotite, ± K-feldspar.</p><p>Vein minerals often show strong zoning, which is especially expressed in amphiboles clearly visible by their variation in color ranging from brown to green corresponding to compositions from pargasite via pargasitic amphiboles, magnesiohornblendes to tremolite/actinolite. Moreover, zoning patterns can be observed in plagioclases from the veins, in which their An contents vary from An<sub>34</sub> down to An<sub>5</sub>. This is distinctly lower than in the plagioclases of the host gabbros, which are virtually unzoned.</p><p>Clinopyroxenes at the contact between felsic vein and host gabbro show reactions either towards orthopyroxene or amphibole. TiO<sub>2</sub> in brown pargasites in the host rock at the contact is enriched (up to ~4.6 wt%), whereas counterparts of the same crystals in the felsic veins are distinctly lower in TiO<sub>2</sub> varying from ~2.5 wt% down to 0.1 wt% TiO<sub>2</sub>, associated with variation in color from brown to green. Calculated equilibrium temperatures based on Ti-content in amphibole (Ernst & Liu, 1998), consequently lead to higher formation temperatures for amphiboles in the host gabbro (up to ~1000 °C) compared to their counterparts in the veins, ranging from ~890 °C to ~500 °C.</p><p>Amphiboles contain ~0.2 wt% F and distinctively lower contents in Cl (with one exception found). Most amphiboles at the contact show a core-rim evolution trend with decreasing F and increasing Cl content, implying a magmatic formation with increasing influence of processes involving a hydrothermal fluid. Only one out of twenty-two investigated samples shows a trend vice versa.</p><p>The record of eutectic crystallization expressed by granophyric structures of quartz and plagioclase indicates that the felsic veins crystallized from a melt.</p><p><em>Ernst, W. G., & Liu, J. (1998). Experimental phase-equilibrium study of Al-and Ti-contents of calcic amphibole in MORB—A semiquantitative thermobarometer. American mineralogist, 83(9-10), 952-969.</em></p>

In situ Composites: A Review

The review of the works on the fabrication-technology studies, patterns of structure formation, and properties of in situ composites is presented. The main advantage of in situ (natural) composites is the thermodynamic stability of their composition and the coherence (conjugation) of the lattices of the contacting phases. All these ones provide the composite with a high level of the physical and mechanical properties. As shown, composite materials of this type are formed in the process of directed phase transformations, such as eutectic crystallization, eutectoid decomposition, etc., caused by a temperature gradient, as well as a result of diffusional changes in composition. The conditions for the growth of in situ composites are formulated. The mechanisms of growth of composite structures of the eutectic type are considered. The factors influencing on the morphology of structures of the eutectic type are indicated. The considered technological methods make it possible to obtain materials with predetermined properties, in which the size, volumetric composition, and spatial arrangement of phases are characteristic of in situ composites. The paper provides a large number of examples of in situ composites: from low-melting Bi-based alloys to refractory eutectics based on Mo and W (Bi–MnBi, Cd–Zn, Al–Al3Ni, Al–Al4La, Al–Al10CaFe2, Al–Al9FeNi, Al–Al3Zr, Al–Al3Sc, Au–Co, Si–TaSi2, Cr–HfC, Cr–ZrC, Cr–NbC, Cr–NbC, Cr–TaC, Nb–Nb5Si3, Mo–ZrC, Mo–HfC, W–TiC, W–ZrC, W–HfC, etc.). Processes and aspects of structure formation are considered. The influence of additional doping on the structure and properties of composite materials of the eutectic type of binary systems, as well as the features of the structure formation of ternary colonies in the composite are considered.

The Application of ATD and DSC Methods to Study of the EN AC-48000 Alloy Phase Transformations

Tests concerning EN AC 48000 (AlSi12CuNiMg) alloy phase transition covered (ATD) thermal analysis and (DSC) differential scanning calorimetry specifying characteristic temperatures and enthalpy of transformations. ATD thermal analysis shows that during cooling there exist: pre-eutectic crystallization effect of Al9Fe2Si phase, double eutectic and crystallization α(Al)+β(Si) and multi-component eutectic crystallization. During heating, DSC curve showed endothermic effect connected with melting of the eutectic α(Al)+β(Si) and phases: Al2Cu, Al3Ni, Mg2Si and Al9Fe2Si being its components. The enthalpy of this transformation constitutes approx. +392 J g-1. During freezing of the alloy, DSC curve showed two exothermal reactions. One is most likely connected with crystallization of Al9Fe2Si phase and the second one comes from freezing of the eutectic α(Al)+β(Si). The enthalpy of this transformation constitutes approx. -340 J g-1. Calorimetric test was accompanied by structural test (SEM) conducted with the use of optical microscope Reichert and scanning microscope Hitachi S-4200. There occurred solution’s dendrites α(Al), eutectic silicon crystal (β) and two types of eutectic solution: double eutectic α(Al)+β(Si) and multi-component eutectic α+AlSiCuNiMg+β.

Nickel in Compacted Graphite Iron

The paper presents results of the research work concerning effects of nickel concentration on the crystallization process, microstructure and selected properties of the compacted graphite iron. Compacted graphite in the cast iron was obtained with use of the Inmold process. The study has comprised the cast iron containing nickel up to concentration providing obtainment of austenitic microstructure of the matrix. The effect of the nickel on temperature of the eutectic crystallization was specified. It has been presented composition of the cast iron matrix in function of nickel concentration in a casting with wall thickness of 3 mm and 24 mm. Moreover, it has been presented conditions defining the possibility of obtaining an austenitic and martensitic compacted graphite iron. Effect of the nickel on hardness of the cast iron was described.

Effect of Copper on the Crystallization Process, Microstructure and Selected Properties of CGI

The paper presents the results of the research on the effect of copper on the crystallization process, microstructure and selected properties of the compacted graphite iron. Compacted graphite in cast iron was obtained using Inmold process. The study involved the cast iron containing copper at a concentration up to approximately 4%. The effect of copper on the temperature of the eutectic crystallization as well as the temperature of start and finish of the austenite transformation was given. It has been shown that copper increases the maximum temperature of the eutectic transformation approximately by 5°C per 1% Cu, and the temperature of the this transformation finish approximately by 8°C per 1% Cu. This element decreases the temperature of the austenite transformation start approximately by 5°C per 1% Cu, and the finish of this transformation approximately by 6°C per 1% Cu. It was found that in the microstructure of the compacted graphite iron containing about 3.8% Cu, there are still ferrite precipitations near the compacted graphite. The effect of copper on the hardness of cast iron and the pearlite microhardness was given. This stems from the high propensity to direct ferritization of this type of cast iron. It has been shown copper increases the hardness of compacted graphite iron both due to its pearlite forming action as well as because of the increase in the pearlite microhardness (up to approx. 3% Cu). The conducted studies have shown copper increases the hardness of the compacted graphite iron approximately by 35 HB per 1% Cu.