Composite electrochemical coatings (CECs) are perceived as the result of the electrochemical reduction of metal from an electrolyte in which dispersed phase particles are present. During the formation of the coating, particles are included in its volume and a composite layer is formed that has increased performance characteristics. The article discusses a different approach based on crystallization of the strengthening phase from an electrodeposited layer of a Ni–W alloy of nonequilibrium composition. It has been shown that the optimal heat treatment mode, which ensures maximum microhardness, leads to the formation of a nanostructured matrix from a solid solution of tungsten in nickel and the crystallization of NiW and Ni4W reinforcing particles. The structure of such a coating corresponds to the structure of classical CECs.

Determining the temperature of the polymorphic phase transformation of austenite into delta-ferrite (Ac-4) is of great practical importance for ensuring deformability during hot plastic deformation of high-chromium martensitic and martensitic-ferrite steels, as it allows to exclude the formation of cracks in the steel billet during deformation. By limiting the heating temperature for hot plastic deformation, it is possible to prevent the segregation of delta-ferrite, the formation of which leads to the appearance of cracks along the boundaries of its section with austenite. In this article, the temperature of phase transformation was determined for the steel grade 07-Cr12-Ni-Mo-V-Nb martensitic ferritic class. Three industrial smelting with different content of alloying elements within the steel grade composition were investigated. Ac-4 temperature was determined by differential scanning calorimetry (DSC), X-ray phase analysis and dilatometric method. Dilatometric and DSC studies were conducted under the same heating rate and showed similar results in the temperature range 1155-1181 degrees C for all smelting. The temperature of transformation of austenite into delta-ferrite under continuous heating is identified more clearly as a result of measuring the heat flow of the DSC method than by measuring the elongation of the sample by the dilatometric method. X-ray phase analysis showed lower temperature values <1150 degrees C, however, they can be considered the most accurate, since this method is a direct method for determining the phase composition of materials due to the comparability of the wavelength of the X-ray radiation and the size of the crystal lattice, thereby obtaining diffraction reflections not from atoms, but from different planes of the crystal lattices. The increased values of DSC and the dilatometric method are associated with continuous heating, during which the fixation of the phase transformation temperature occurs in the presence of a certain content of the new phase. Thus, as a result of research it is established that the temperature of heating for hot plastic deformation should not exceed the temperature of 1150 degrees C.

The size and volume fraction of fine particles of secondary β -phase formed during hardening heat treatment of pseudo-β-titanium alloy VT22 are determined using low-angle scattering of neutrons, x-ray diffractometry, electron back-scatter diffraction, and transmission microscopy combined with x-ray spectral microanalysis. Based on comprehensive use of experimental data obtained by methods of different restriction levels analysis is conducted for the size, shape, elemental composition, and volume content of fine particles obtained after different versions of hardening heat treatment. Activation of β -phase decomposition energy due to low-temperature aging is determined.

Проведено исследование физико-химических параметров ассоциатов не стабилизированных наночастиц (НЧ) меди, полученных плазмохимическим способом. Для определения размеров ассоциатов НЧ использовали оптические методы, включая атомно-силовую микроскопию, спектрофотометрию и флюорометрию. Размеры НЧ меди варьировали от 30 до 75 нм, а размеры ассоциатов НЧ — от 481.1 до 1037 нм. Проведен анализ фазового состава НЧ меди методом рентгеновской дифрактометрии с использованием многофункционального рентгеновского дифрактометра Rigaku Ultima IV. На поверхности ассоциатов НЧ обнаружена оксидная пленка без примеси органических молекул. Изучали действие НЧ меди на культуру клеток А549. Обнаружено изменение биохимических показателей сыворотки крови белых беспородных мышей под влиянием НЧ меди. Выявлен противоопухолевый эффект НЧ меди и сопоставлена его выраженность при разных способах введения НЧ животным с фибросаркомой (С-45) и лимфосаркомой Плисса.

The physicochemical parameters of associates of unstabilized copper nanoparticles (NPs) obtained by the plasma-chemical method were studied. Optical methods were used to determine the size of NP associates, including atomic force microscopy, spectrophotometry, and fluorometry. The sizes of copper NPs varied from 30 to 75 nm, and the sizes of NP associates, from 481.1 to 1037 nm. The phase composition of copper NPs was analyzed by X-ray diffractometry using a Rigaku Ultima IV multifunctional X-ray diffractometer. An oxide film without an admixture of organic molecules was found on the surface of NP associates. The effect of copper NPs on an A549 cell culture was studied. A change was observed in the biochemical parameters of blood serum of outbred mice under the influence of copper NPs. The antitumor effect of copper NPs was revealed, and its intensity was compared to different methods of administering NP to animals with fibrosarcoma (S-45) and Pliss lymphosarcoma.

An important task in developing new materials is the study of their structure (substructure). The present study uses a number of complementary methods to determine the size, morphology, phase composition and volume fraction of dispersed precipitates in high-strength medium-carbon steel tempered in the temperature range of up to 600 degrees C. The methods of small-angle neutron scattering, X-ray and neutron diffraction were used. Such an advantage of neutrons as the ability to use large samples, which significantly increases the maximum permissible grain size to obtain statistically reliable results and takes into account texture data, explains the use of neutron sources along with the X-ray ones. The disadvantages include a lower resolution and more complex equipment. The combined use of different techniques made it possible to determine the kinetics of structural changes in the dispersed particles during tempering of steel. The increase in tempering temperature up to 300 degrees C results in a decrease in the amount of retained austenite. At the tempering temperature of 300 degrees C, the growth of Fe3C particles instead of retained austenite starts and continues up to 600 degrees C up to which the studies were done. The phases of retained austenite and cementite were identified by means of neutron diffraction, while changes in sizes were determined by means of small-angle neutron scattering. The results obtained do not contradict the previous transmission electron microscopy data. A comprehensive study by means of diffraction and scattering methods of X-rays and neutrons allows one to obtain exhaustive information about disperse particles in steels.

Disperse precipitates in high-strength high-chromium martensite-ferrite steel of 0.15C–12Cr–Ni–Mo–W–V composition after various modes simulating the after-forging annealing were investigated. The investigated metal after holding at 1050°С for 1 h and quenching in oil was heat treated (HT) in two modes: HT 1—the after-forging annealing at 700°С for 6 h to relieve stresses; HT 2—HT 1 with the following isothermal annealing, heating to 1000°С, short holding, cooling to 700°С, and holding for 16 h. On the basis of the combined research, including optical metallography, X-ray phase analysis, transmission electron microscopy, and small-angle X-ray scattering, it was found that the tempered martensite structure with the ferrite phase of less than 1% was formed in the steel after HT 1; and after HT 2, transition from the martensiteferrite to ferrite-pearlite state took place; significant growth of carbides of the (Fe Cr) 23 C 6 type and substructural components (coherent scattering areas, electron density inhomogeneity) was found; and finely dispersed particles of vanadium carbide V 2 C about 30 nm in size were formed.

With the aim to prevent crack formation in a fusion zone under surfacing of copper-nickel alloy of high nickel content on aluminum-nickel bronze, we discuss the features of composition and structure of constituent metals caused by displacement of a significant amount of aluminum into the surfacing metal.