Influence of defects on the ductility of liquid 9X2MΦ and 75X3MΦ steel

Viscosimetric data on liquid 9X2MΦ and 75X3MΦ steel taken from working rollers of a reversible rolling mill with different ultrasonic behavior illustrate the influence of defects recorded in ultrasound monitoring on the temperature and time dependence of the liquid steel's kinematic viscosity. A Krautkremer ultrasonic defectoscope is employed in monitoring. The viscosity of the liquid steel is measured by means of damping torsional oscillations of a crucible with melt in heating and subsequent cooling in the range 1500-1580°C. © 2013 Allerton Press, Inc

Modified algorithm of the Riemann problem solution

The algorithm for solving the Riemann problem is considered in detail in the article. The statement of the Riemann problem is presented. The limitations of the algorithm described above and possible ways to overcome them are revealed. An improvement in the solution of the Riemann problem algorithm is presented

Influence of copper additives on the viscosity and stratification of iron melt

Viscosimetric data are obtained for Fe-Cu melts in heating and subsequent cooling of samples with 0-10 wt % Cu. Above the liquidus in the resulting phase diagram, the boundaries of the region where microheterogeneities of colloidal scale exist in the melt are found. © 2013 Allerton Press, Inc

Effect of Atomic Size on the Isothermal Bulk Modulus and Surface Tension of Liquid Metals

The isothermal bulk modulus KTm and surface tension γm of liquid metals at the melting point increase with decreasing atomic size a, and these dependences are similar to one another. It is shown that transition metals with a hexagonal closed-packed and body-centered cubic structure are concentrated above the γm−KTm regression line, and face-centered cubic metals are below this line. In alkali, alkaline earth, rare earth metals, the surface tension γm with a change in the isothermal bulk modulus KTm increases several times more intensively than in transition metals. The reduced quantities of isothermal bulk modulus and surface tension have been introduced. The reduced surface tension demonstrates high coincidence with atomic size parameter a−2, and the reduced isothermal bulk modulus with atomic size parameter a−3. The ratio of the surface tension to the product of the atomic size and the isothermal bulk modulus γm×(aKTm)−1 compares the energy of atoms on the surface and in the bulk. © 2022, The Minerals, Metals & Materials Society and ASM International

The definition of productive reservoirs by the method of fuzzy inference

The lithological classification and allocation of reservoirs are based on the difference of physical and geophysical parameters of rocks. Finding the values of physical and geophysical parameters in some ranges makes it possible to predict the lithology of the formation. The class of information systems based on fuzzy logic provides an effective use of existing knowledge about a certain object. This allows to apply fuzzy logic in intelligent systems of interpretation of well geophysical research materials

Viscosity and separation of Fe-Cu melts

A viscosimetric study of Fe-Cu melts is performed on heating and subsequent cooling of samples. The results of measurements in the above-liquidus part of the phase diagram are used to construct the boundaries of colloid-scale microheterogeneities in a melt. © 2013 Pleiades Publishing, Ltd

Nanocrystalline soft magnetic iron-based materials from liquid state to ready product

The review is devoted to the analysis of physical processes occurring at different stages of production and application of nanocrystalline soft magnetic materials based on Fe–Si–B doped with various chemical elements. The temperature dependences of the kinematic viscosity showed that above a critical temperature, the viscosity of multicomponent melts at the cooling stage does not coincide with the viscosity at the heating stage. Above the critical temperature, the structure of the melt is more homogeneous, the amorphous precursor from such a melt has greater plasticity and enthalpy of crystallization and, after nanocrystallization, the material has a higher permeability. The most effective inhibitor elements are insoluble in α-Fe and form a smoothed peak of heat release during crystallization. On the other hand, the finest nanograins and the highest permeability are achieved at a narrow high-temperature peak of heat release. The cluster magnetic structure of a nanocrystalline material is the cause of magnetic inhomogeneity, which affects the shape of the magnetic hysteresis loop and core losses. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Isobaric Thermal Expansivity and Isothermal Compressibility of Liquid Metals

The relationship between the volumetric thermodynamic coefficients of liquid metals at the melting point and interatomic bond energy was studied. Using dimensional analysis, we obtained equations that connect cohesive energy with thermodynamic coefficients. The relationships were confirmed by experimental data for alkali, alkaline earth, rare earth, and transition metals. Cohesive energy is proportional to the square root of the ratio of melting point Tm divided by thermal expansivity αp. Thermal expansivity does not depend on the atomic size and atomic vibration amplitude. Bulk compressibility βT and internal pressure pi are related to the atomic vibration amplitude by an exponential dependence. Thermal pressure pth decreases with an increasing atomic size. Fcc and hcp metals with high packing density, as well as alkali metals, have the relationships with the highest coefficient of determination. The contribution of electrons and atomic vibrations to the Grüneisen parameter can be calculated for liquid metals at their melting point. © 2023 by the authors

The Effect of Nickel on the Viscosity of Iron‐Based Multicomponent Melts

In this work, we investigated the temperature dependence of the kinematic viscosity of multicomponent Fe72.5‐xNixCu1Nb2Mo1.5Si14B9 melts with a Ni content of up to 12.7 at. %. The peculiarities of the temperature dependence of Ni‐containing melts were explained by the tendency of Ni atoms to surface segregation. Ni atoms are concentrated near the interfaces of the liquid and solid phases in the mushy zone at the stage of melting and restrain the melting of the solid phase. With increasing Ni content, the Arrhenius type of viscous flow begins at a higher temperature. Ni atoms are concentrated at the periphery of clusters, increasing their size and decreasing their mobility. The movement of Ni‐containing clusters increases the activation energy and decreases the kinematic viscosity. The change in the activation energy at a temperature of about 1700 K was associated with a liquid–liquid structure transition (LLST). This structural transition is reversible since it is observed both at the heating and cooling stages. The increase in kinematic viscosity at temperatures above 1900 K was associated with the decomposition of high‐temperature clusters based on cementite and silicon oxides. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.The article was made within the framework of state work No. FEUZ-0836-0020

Electrical resistivity of liquid CuSn, CuSnBi, CuSnBiIn, CuSnBiInCd alloys of equiatomic compositions

The resistivity of liquid CuSn,CuSnBi, CuSnBiIn, CuSnBiInCd alloys of equiatomic compositions are measured using the rotating magnetic field method to obtain information on their liquid structures. The alloys of equiatomic composition we considered as the high-entropy alloys. The results are discussed in the frame of a microheterogeneous structure of a metallic melt. A conclusion is made about the character of the modification of temperature dependence of the resistivity of liquid alloy due this microheterogeneous structure. All the investigated alloys demonstrated the change in the temperature coefficient of the resistivity for heating and cooling. These changes determined the temperature of destruction the microheterogeneous structure of a metallic melt (T∗). The value of temperature T∗ for all alloys was 1070 K (800 °C). The change in the temperature coefficient of the resistivity of the alloys on heating to 1070 K (800 °C) is interpreted using the Nagel-Tauc model. © 2019 Author(s)