Investigation of Two-Phase State of Fe–Cu Melts during Cooling in a Viscometer

Abstract: Fe–Cu alloys can be characterized as a system with immiscible components (IC). This statement is based on a weak mutual solubility in the solid state. In addition, Fe–Cu system stratifies in the liquid state at low carbon content. Alloys with ICs have a simple phase composition of almost pure components, which determines a significant practical interest in these alloys. Manufacturers have technologically succeeded in achieving damping alloys of Fe–Cu–Pb system. With proper technological preparation, the final product can be obtained by combining the properties of pure alloy components in the fraction required for practical application. For example, diamagnetic copper has high electrical conductivity and thermal conductivity in Fe–Cu alloys, while ferromagnetic iron has enhanced strength characteristics compared to copper. When the alloy structure is organized in a certain way, a final product can be obtained with high electrical conductivity and thermal conductivity of copper, enhanced strength properties of iron, or a hard magnetic material with copper ductility. The studies of iron-copper alloys focused on the structural studies and measurements of service properties. At the same time, the dynamics of macro- and microstructure alloy formation were not analyzed. In the present studies, the macrostructure formation dynamics of the solid phase enriched with iron at the crystallization melt process during cooling was studied using high-temperature viscometry. Due to the effect of the melt-cooling rate on the size and morphology of crystallizing inclusions, as well as a significant amount of the two-phase area, special attention was paid to the thermophysical analysis of the measurement mode. Analysis of the reliability of the results obtained was made by the viscosity measurement method. The phase state of Fe–Cu system melts was investigated during cooling by changing the damping factor. The analysis of thermophysical processes occurring during measuring the damping factor was carried out. The measuring process of damping decrement takes place under quasi-equilibrium conditions and the cooling rate is close to zero. There are no temperature gradients, both in radius and in height. For compositions Fe50Cu50, Fe40Cu60, and Fe30Cu70, the precipitation dynamics of the solid phase was determined. © 2019, Allerton Press, Inc.