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The effect of accelerated Ar+ ions on the crystallization process and magnetic properties of nanocrystalline Fe72.5Cu1Nb2Mo1.5Si14B9 alloy has been studied using X-ray diffraction analysis, transmission electron microscopy, thermomagnetic analysis, and other magnetic methods. Irradiation by Ar+ ions with an energy of 30 keV and a fluence of 3.75 × 1015 cm–2 at short-term heating to a temperature of 620 K (which is 150 K below the thermal threshold of crystallization) leads to the complete crystallization of amorphous alloy, which is accompanied by the precipitation of the α-Fe(Si) solid solution crystals (close in composition to Fe80Si20), Fe3Si stable phase, and metastable hexagonal phases. The crystallization caused by irradiation leads to an increase in the grain size and changes the morphology of grain boundaries and volume fraction of crystalline phases, which is accompanied by changes in the magnetic properties.

The composition of the ladle slag in units designed for the secondary treatment of steel needs to be optimized in order to increase the service life of the units’ linings. On the one hand, the slag subjects the refractories to chemical wear. On the other hand, under certain conditions the slag is capable of forming a protective crust inside the units. The Nizhniy Tagil Metallurgical Combine has chosen certain refractories for the most heavily worn part of the lining of its vacuum chambers, since only the installation of a lining of a differentiated design that equalizes the rate of wear around the lining’s perimeter will allow the desired effect to be obtained from optimizing the composition of the slag. An efficient composition for the slag was also chosen, the slag having high contents of MgO and Al2O3. The use of such a slag helps form a protective slag crust of the composition MgO·Al2O3 on spinel refractories having the compositions MgO·Cr2O3 and MgO·Al2O3.

The structural state of the Cu-7.1% P and Cu-7.1% P-2% Ag solder melts are studied by viscometry and densitometry over a wide temperature range. The evolution of the microstructure of Cu-7.1% P solder ingots after heating of the melt at high temperatures is detected. The experimental results are interpreted using the concept of a microheterogeneous structure of a metallic liquid. 1 The alloy composition is given in wt %. 2 Trademark of a copper-phosphorus (Cu-7.1% P) solder.

We have studied composition dependences of kinematic viscosity for Fe-Cu melts with the aim of determining the temperature and composition ranges where chemically inhomogeneous Fe-Cu melts exist. Measurements were performed during heating and cooling in the temperature range from 1550 to 1700A degrees C. Evidence has been found for chemical inhomogeneity of Fe-Cu melts in the form of both microheterogeneity and a nonuniform distribution of dissimilar atoms. We have determined the temperature and composition ranges of microheterogeneity in the phase diagram of the Fe-Cu system. The nonuniform Fe and Cu distributions have been accounted for in the quasi-chemical approximation of the theory of irregular solutions, which has been used to evaluate the short-range order parameter and integral enthalpy of mixing.

Microheterogeneity and crystallization conditions of the equiatomic high-entropy CuNiAlCoFe alloy were studied by measuring the viscosity during heating/cooling, as well as visualizing the microstructure after solidification. The CuNiAlCoFe liquid alloy showed different temperature dependences of viscosity upon heating to 2070 K and subsequent cooling. Since the coinciding part of the temperature dependences was absent, complete destruction of the microheterogeneity of the melt after heating to 2070 K did not occur. Heating the melt to higher temperatures was not possible due to the evaporation of the metal. The melt viscosity during cooling is higher than that during heating; this is observed when microheterogeneity is dispersed. The CuNiAlCoFe alloy obtained as a result of the experiment at a crystallization rate of 10 K/s had a typical microstructure of cast dendrite. Dendrites consisted of a eutectic (α-Al+CuAl2+Cu4NiAl7) and included primary crystals of CoCu2Al7 and FeCu2Al7. The interdendritic space contained small Cu4NiAl7 crystals.

By using x-ray diffraction analysis, small-angle x-ray scattering, resistometry, and electrochemical voltammetry, the effect of thermally pretreating the melt on the structure, as well as crystallization and electrochemical behavior, of rapidly quenched bands of an alloy Fe76.1Cu1.0Nb3.0Si13.8B6.1 is investigated. It is shown that, by varying the production conditions of rapidly quenched alloys, one can substantially affect their amorphous-nanocrystalline structure and increase the corrosion resistance.

X-ray diffraction analysis, auger spectroscopy and electrochemical measurement showed that, by varying the temperature of starting melt, it is possible to change the surface crystallization degree of quenched metallic glass of the Fe76.1Cu1.0Nb3.0Si13.8B6.1 composition, while the presence of crystallites of an ordered α-Fe(Si) solid solution and the air-oxide film formed during the quenching of bands allows improving their corrosion-electrochemical characteristics.

Giant domain walls with a width of ∼7 μm are observed on the surface of a ferromagnet — an amorphous magnetically soft alloy. A magnetooptic investigation shows that the walls have a Neel structure in the subsurface region. The subsurface structure of these walls differs substantially from that of the narrower walls previously observed in iron, Permalloy, and amorphous materials. According to the theoretical model of Scheinfein and co-workers, which relates the width of an asymmetric Bloch wall in the bulk with the width at the surface, the width of the wall in the bulk is estimated to be 3–4 μm.

A wide range of physical properties of liquid Co-based alloys has been investigated. The temperature dependencies of kinematic viscosity have shown to be nonmonotonic. The correlation between the viscosity and some magnetic properties of amorphous ribbons has been established. Higher viscosity of the melt leads to better magnetic properties: higher maximum permeability, lower coercive force. The re-melting leads to increasing of the magnetic properties of produced ribbons. The optimization of temperature regime of melt preparing before amorphization has been proposed.

The article examines questions of the automation of the finite-element solution of heat-conduction problems with phase transformations and mobile boundaries. The main principles of devising an algorithm and the results of a numerical experiment are given.