The fraction of the amorphous phase remaining after the crystallization of amorphous alloys with one (P), two (P, Si) and three (P, Si, C) amorphizers is determined by X-ray diffraction. An increase in the fraction of a single-phase matrix is found to inhibit the crystallization during fast photon irradiation and heat treatment. Differential scanning calorimetry demonstrates that an increase in the number of amorphizers leads to a decrease in the crystallization rate of a structure, which is stable in an industrial atmosphere.

— Using a variety of characterization techniques (differential scanning calorimetry, X-ray diffraction, high-resolution transmission electron microscopy, resistivity measurements, nanoindentation, and uniaxial tension testing), we have studied structural changes produced in the amorphous phase of the Fe 77 B 7 Nb 2.1 Si 13 Cu 0.9 alloy by heating in vacuum to 750°C and lamp processing (LP) with the use of pulsed xenon lamps to a fluence F = 120 J/cm 2 on the sample surface. Increasing the temperature or fluence leads to three stages of structural transformations: structural relaxation of the amorphous phase below 450°C and two stages of crystallization, which show up as nonmonotonic behavior of the hardness and local plasticity of the samples. With a common character of the structural changes, the effect of LP shows up as an increase in crystallization rate (the processing time is 200 times shorter). In both cases, the fraction of plastic strain in indentation work in amorphous and crystallized samples is 25% larger than that in amorphous–crystalline composites. It has been shown that irreversible deformation of amorphous samples by uniaxial tension leads to structural relaxation and an increase in the size of the relaxation zone.

Abstract—The estimation of the magnetic properties of the amorphous alloys Fe–P–Si and Fe–P–Si–Mn–V–C fabricated from naturally alloyed ferrophosphorus and a 2NSR-type alloy (Fe–Ni–Si–B–Nb–Cu) shows that they are comparable in saturation induction and coercive force. However, the materials made of ferrophosphorus have a lower cost and can be used as ferrocomposite materials.

The corrosion resistance of metallic amorphous alloys (AAs) Fe80.2P17.1Mo2.7, Fe80.5P18.4Nb1.1, Fe98 –xPxSi2 (x = 14, 16, 20), Fe76.5P13.6Si4.8Mn2.4V0.2C2.5 in a 0.1 M solution of Na2SO4 (pH 6.25) and its change due to structural relaxation, nanocrystallization, and local deformation are studied. The activation of structural relaxation by photonic treatment is shown to increase the corrosion resistance of AAs. As the phosphorus content in the Fe98 ‒ xPxSi2 system decreases, the corrosion resistance of AAs decreases because of partial crystallization, which is accompanied by the formation of iron phosphides during rapid cooling of a melt, and silicon segregation at phase boundaries. The formation of local deformation zones in the near-surface layer of Fe76.5P13.6Si4.8Mn2.4V0.2C2.5 AA decreases its corrosion resistance. The niobium alloying of Fe‒P AAs is shown to be effective to decrease the corrosion rate.

In order to determine the mechanism of plastic deformation, the hardness and local plasticity of amorphous Fe78P20Si2 alloy are compared at different stages of its crystallization activated by thermal treatment at 300–750°C or short-term photon treatment with a radiation dose coming to the sample of 10–60 J/cm2. The phase composition and structure were investigated by X-ray diffractometry and high-resolution transmission electron microscopy. With the same sequence of structural changes, the crystallization rate under photon treatment is more than two orders of magnitude higher than that under thermal treatment, which indicates the effect of a high rate of input of the process activation energy. The nonmonotonic dependence of the hardness, elastic modulus, and the proportion of plastic strain in the indentation work is found, depending on the annealing temperature or radiation dose received by the sample, as a result of structural changes in the alloy. The local plasticity of the initial alloy and fully crystallized alloy are close in magnitude. Based on the features of the crystal structure of the Fe3P phase (the impossibility of the dislocation mechanism of plastic deformation) and assuming that the structural unit (tetrahedral Fe3P cluster) of the crystallized and amorphous alloy is identical, a conclusion was formulated about the cluster mechanism of plastic deformation of the amorphous alloy.

With the aim of establishing the mechanism of plastic deformation the local hardness and plasticity of the amorphous alloy (AA) Fe78P20Si2 at different stages of its crystallization, thermal annealing (TA) at 300-750оС or short-term photonic treatment (PT) with the dose received at the sample radiation of 10-60 J/cm-2 is mapped. The phase composition and structure were investigated by x-ray diffractometry and high-resolution transmission electron microscopy. With a general sequence of structural changes, the crystallization rate at the PT is more than two orders of magnitude greater than TA that indicates the effect of a high rate of input of the activation energy of the process. The nonmonotonic dependence of hardness, modulus of elasticity and the proportion of plastic deformation in the work of indentation depending on the annealing temperature or the dose of radiation entering the sample as a result of structural changes in the alloy was established. In this case, the local plasticity of the initial alloy and the fully crystallized one are close in magnitude. Based on the features of the crystal structure of the Fe3P phase (respectively, the impossibility of the dislocation mechanism of plastic deformation) and on the assumption of the identity of the structural unit (tetrahedral cluster Fe3P) of the crystallized and amorphous alloy, the conclusion about the cluster mechanism of plastic deformation of the as is formulated.

The electrochemical behavior of amorphous and nanocrystalline soft magnetic Fe 79 P 13 Si 5 V 3 alloy in a 0.1 M Na 2 SO 4 solution has been studied. Mössbauer studies show that the electrochemical characteristics of the alloy are comparable with those of an Finemet Fe 77 Si 13 B 7 Nb 2.1 Cu 0.9 alloy, whereas the studied alloy is inexpensive and can be prepared using natural alloy ferrophosphorus containing vanadium and silicon.

We have studied the structural transformations and deformation behavior of an amorphous Al85Ni10La5 alloy during nanoindentation and uniaxial tension tests and assessed the influence of crystalline phases resulting from lamp processing and heat treatment. Our results confirm the high effectiveness of lamp processing: at identical phase compositions, the lamp processing time is shorter by more than two orders of magnitude. The microplasticity of the amorphous alloy has been shown to manifest itself in both nanoindentation and uniaxial tension tests. The high proportion of local plasticity in the work of indentation has been accounted for in terms of possible intercluster sliding. The observed lamp processing- and heat treatmentinduced changes in the hardness of the alloy reflect changes in its phase composition and the percentages of the amorphous and crystalline phases, which does not rule out a cluster mechanism of local deformation or its deceleration by nanocrystalline phases in the amorphous–nanocrystalline structure.

The effect of the nanocrystallization of amorphous soft magnetic Fe-P-Nb alloys on their electrochemical behavior in a damp SO2-polluted industrial atmosphere is studied. It is shown that their electro-chemical characteristics shit toward positive values when the phosphorus content in the Fe-P-Nb alloys increases and when they undergo nanocrystallization from an amorphous state.

We have studied the mechanical properties and corrosion resistance of an amorphous Fe 76.5 P 13.6 Si 4.8 Mn 2.4 V 0.2 C 2.5 alloy and their response to nanocrystallization as a result of brief lamp processing and heat treatment. The results demonstrate that the lamp processing time needed to obtain a given phase composition through partial crystallization of the amorphous alloy is two orders of magnitude shorter than the corresponding heat treatment time. We have found lamp processing conditions that ensure the formation of an amorphous–nanocrystalline composite with a twofold increase in hardness, without loss of plasticity. It has been shown that, with increasing loading rate during nanoindentation, the hardness of the alloy decreases because of the increase in plasticity, which shows up as the formation of a larger number of shear bands. Under uniaxial tension, the material exhibits microplasticity, which may be due to intercluster sliding, with the amorphous structure retained. The corrosion resistance of the as-prepared amorphous alloy in a medium contaminated with sulfur dioxide exceeds that of the partially crystallized alloys.

Nanocrystalline soft magnetic Finemet alloys, which are currently used in power electrical engineering and electrical equipment, are alloyed with expensive and scarce metals (Nb, Cu). We searched for low-cost soft magnetic alloys that are comparable with Finemets in the corrosion resistance.

The magnetic properties and Mossbauer spectra of amorphous 2NSR alloy samples are investigated after quenching and after tempering for different times at 520°C. After quenching, the alloy is inhomogeneous. Tempering of alloy samples below the crystallization temperature (540°C) raises the Curie temperature and the mean superfine field at the iron nuclei. Tempering leads to complex changes in the saturation magnetization. The changes in magnetic properties are analyzed.

The study is devoted to the choice of the optimum composition of a soft magnetic amorphous Fe–P–Sialloy, which is comparable with the (Fe77Si13B7Nb2.1Cu0.9) FINEMET alloy in corrosion resistance and is passivated at lower critical currents in a 0.1 M Na2SO4 solution. The alloy can be prepared from naturally alloyed ferrophosphorus.

Методом рентгеновской дифрактометрии сопоставлены структурные изменения, происходящие в результате термической обработки и фотонной обработки (ФО) аморфного сплава (АС) Fe78P20Si2. Показано, что основной эффект ФО – ускорение процесса кристаллизации. В режиме наноинтентирования, не приводящего (по результатам ПЭМ) к кристаллизации под действием сосредоточенной нагрузки, определены твердость (8 ± 0.3 ГПа) и модуль Юнга (130 ± 10 ГПа) АС. Определен режим формирования при ФО аморфно-нанокристаллического композита с твердостью, почти в два раза превышающей твердость исходного АС при сохранении пластичности.

The structural changes induced in an amorphous Fe 78 P 20 Si 2 alloy by heat treatment and lamp processing have been compared using X-ray diffraction. The results demonstrate that the main effect of the lamp processing is to increase the crystallization rate. Under nanoindentation conditions that do not lead to crystallization under the action of a concentrated load (as verified by transmission electron microscopy), we have determined the hardness (8 ± 0.3 GPa) and Young’s modulus (130 ± 10 GPa) of the amorphous alloy. Lamp processing conditions have been found that lead to the formation of an amorphous-nanocrystalline composite whose hardness is almost twice that of the parent amorphous alloy, without loss of plasticity.

This paper examines the electrochemical behavior and structural changes of an Fe-P-V alloy in a 0.1 M Na2SO4 solution modeling a SO2-contaminated humid atmosphere.

The changes in the phase composition and the mechanical and magnetic properties resulting from the nanocrystallization of an Fe 80.2 P 17.1 Mo 2.7 amorphous alloy activated by heat or fast photon (xenon lamp radiation) treatment are compared using X-ray diffraction, Mössbauer spectroscopy, transmission electron microscopy, and hardness measurements. The initial stages of crystallization of the amorphous alloy have been detected.