Рroduction of 70%Cu–30%Fe alloy by SHS metallurgy and electrometallurgy. Comparative analysis of microstructures

Abstract

The influence of different methods used to produce Fe–Cu alloys from immiscible components was studied. Alloys with limited solubility (LS) or pseudoalloys (PA) in a liquid or solid state have long been impossible to obtain with traditional metallurgy methods. This is why developing low-cost and simple technologies to produce such alloys and materials based on them with a possibility to set the required level of physical and mechanical properties is still a relevant problem. This study uses energy-efficient SHS metallurgy method to produce a pseudoalloy with a composition, wt.%: 70Cu–30Fe from oxide materials for the first time. This technology offers using chemical energy generated in the reaction of highly exothermic thermit compositions (in a combustion mode) making it a very energy-efficient method for cast material production. Short synthesis time (tens of seconds), and top surface of ingots protected from oxidation with an oxide melt (Al2O3) enables synthesis in atmospheric conditions. Rods with the same composition were obtained using single-stage vacuum induction remelting from pure (impurity-free) Fe and Cu components for comparative structural studies of alloy sample components. It was found that high melting temperatures of the SHS alloy provides higher solubility of Cu in Fe. Then, when crystallized, structural components are released in the form of small dispersed particles throughout the volume and form a hierarchical structure typical for the SHS alloy only. 70Cu–30Fe alloys produced in a combustion mode (SHS) have a homogeneous structure with structural components distributed uniformly throughout the sample volume, which can be of great practical interest, in particular, for making isotropic and anisotropic hard-magnetic materials with high magnetic energy.