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The interaction of Ra(NO3)2 and RaCO3 with metallic Fe, Ni, Cr, Ti has been studied. Experimental samples were fabricated by deposition of water-alcohol suspensions of radium salts onto substrates made of the corresponding metals, followed by evaporation and calcination for 7–14 h at a temperature of 800°C. According to the results of an X-ray phase analysis, mixed oxides of composition RaMOx, where M = Fe, Cr, Ti, Ni, in joint calcination of Ra(NO3)2 and RaCO3 with Fe, Ni, Cr, Ti metals.

We successfully refined a cheap commercial boron powder by means of high-energy ultra-sonication and utilized it in synthesis of bulk MgB2. Rietveld phase analysis of X-ray diffraction pattern revealed completely formed MgB2 with a low amount of MgO. MgB2 bulk prepared of boron ultra-sonicated in ethanol for 15 min showed self-field Jc of around 300 kA/cm2 at 20 K without any compromise in Tc (~39 K). Pinning analysis based on Dew-Hughes expression showed major pinning contribution from grain-boundary pinning (~95.5%), along with a slight contribution from point pinning (4.5%). The microstructure study detected a system of large MgB2 grains (hundreds nm large) and 10–20 nm sized particles, possibly Mg-B-O, formed at MgB2 grain boundaries.

Solid-phase equilibria in the Tm–Te system and the thermodynamic properties of thulium tellurides are studied via electromotive force (EMF) method and X-ray phase analysis. Experimental data show that compounds TmTe, Tm2Te3, and TmTe3 form in the system. The partial thermodynamic functions of TmTe and Tm in alloys are found for the first time from EMF measurements in concentration cells, relative to TmTe and Tm electrodes at 300–450 K, from which standard thermodynamic functions of formation and standard entropies of intermediate compounds are calculated.

Yttrium-aluminum garnet (YAG) nanoparticles are synthesized by the coprecipitation of yttrium and aluminum hydroxides in a microreactor with freely impinging jets, followed by the thermal treatment of the coprecipitation products. According to the results of X-ray phase analysis, the coprecipitated hydroxides are X-ray amorphous. Analysis of the product of the thermal treatment of hydroxides at 1000°C for 10 min indicates the formation of Y3Al5O12 crystals. The method developed by us makes it possible to carry out the synthesis quickly, ensures low energy consumption, does not require laborious operations, and is technologically advanced and easily scalable.

The aim of this study is to produce highly dense Si3N4 based composites with good mechanical properties and bioactivity. Si3N4 ceramics without using sintering aids, Si3N4-HA and Si3N4-HA-GNP based composites have been produced by spark plasma sintering (SPS) at temperatures of 1525–1550°C. The effect of reinforcement type and content on the densification behavior, phase analysis, microstructural development, mechanical properties, and in-vitro bioactivity behavior of Si3N4 were systematically investigated. Monolithic Si3N4 that contains a high amount of β-Si3N4 phase (~87 wt%) was produced by nearly full densification (~99%). Hydroxyapatite (HA) was used as a starting powder during the preparation of binary and triple composites to provide bioactivity to Si3N4, and after sintering, HA transformed into tricalcium phosphate (β-TCP and α-TCP) polymorphs. The incorporation of GNPs had a positive effect on the stability of β-TCP phases at higher sintering temperatures. The improvement in indentation fracture toughness of the samples with GNP reinforcement was mainly attributable to pull-out and crack deflection mechanisms. In-vitro bioactivity of GNP added composites enhanced with increasing α-TCP content. More calcium phosphate-based particle formation was observed in Si3N4-HA-GNP composites compared to the Si3N4-HA.

We report a refractive index tip fiber optic sensor based on a modal interferometer coated with a thin copper film. This device can be used for solute concentration in aqueous mixture measurement. The copper film increases the device reflectivity and, as a result, increases the multimodal interference pattern visibility. To validate the sensor device, different water-glycerol weight concentrations were used in the range from 0 to 45 Glycerol %. The recorded spectral responses show a redshifting, and a sensitivity of 19 pm / (Glycerol % by weight) from 0 to 18 % and 4.7 pm / (Glycerol % by weight) from 18 to 45 % was achieved. Besides, using a phase analysis we calculated a sensitivity of -15 rad/RIU.

Self-propagating High-temperature Synthesis (SHS) process is used to prepare Aluminium dodecaboride (AlB12). The phase analysis results of preparing AlB12 with Al and B2O3 as raw materials show that under air and argon conditions, the self-propagating and acid-washed self-propagating powders all have α-Al2O3 impurities when Mg, Al and B2O3 are used as raw materials. The phase analysis results of the preparation of AlB12 show that under argon conditions, the self-propagating and acid-washed, self-propagating powder has un-removable MgAl2O4 impurities, and the root cause of the low purity of AlB12 prepared by the self-propagating method is the presence of un-removable impurities.

This paper reports a study into the phase composition and microstructure of tungsten ore concentrate after carbon-thermal reduction at different O:C ratios in the charge. This is required for determining those indicators that reduce tungsten loss through the sublimation of oxide compounds when processing ore concentrates, as well as when using reduced tungsten-containing doping additives. The study results have established that the reduced tungsten concentrate at the O:C ratio in the charge within the interval of 1.33‒2.30 contained the phases of W, W2C C, C, WO2. The microstructure demonstrated a spongy and disordered character. Together with W, the Mo, Si, Ca, Al impurities were present in the reduced products. The main elements identified at the sites studied had the following limiting content,% by weight: O – 5.01–17.32; C – 0.84–4.23; W – 61.21–86.78; Mo – 1.57–7.51; Si – 2.07–9.06; Ca – 1.34–11.30; Al – 0.27–0.40. The micro-inclusions at the examined surface areas acquired different complex shapes. There were traces of the process of caking between the particles. The analysis of the resulting data has shown that the most preferred ratio of O:C in the charge was 1.65. In this case, there is no lack of carbon and there is a predominance of W in the phase composition with a relatively little manifestation of the W2C phases, carbon, as well as the residual part of WO2. The post-reduction of the oxide component would occur during the doping process. The sponge structure contributes to a higher dissolution rate compared to standard tungsten ferroalloys. Lack of compounds with a relatively high propensity for sublimation does not require any special conditions to prevent the loss of tungsten in the gas phase, which increases the degree of assimilation of the target element

In the present work, CZTSe (Cu2ZnSnSe4) films were deposited by Thermal evaporation technique. The as deposited films were annealed at 450 °C for 10 min. To incorporate Sulfur in the CZTSe film and to replace some of the Se by S, the films (as deposited and annealed) were treated with Thiourea solution (1 Molar). Further the films were annealed at 450 °C for 10 min after the thiourea treatment. Finally the films were characterized for phase analysis using XRD and Raman. The composition analysis was done using EDXRF. The band gap of the film varies according to the S/Se ratio. Compositional analysis as obtained from ED-XRF, shows the required ratio of Cu/(Zn + Sn) 1 for all the films. The conductivity and mobility of the films changes with variation in sulfur and selenium ratio. The obtained electrical and optical properties of CZTSe absorber layer after thiourea treatment are suitable for device application.

The possibility of high electrical conductivity of dry sliding electrical contact against a molybdenum counterface was studied. It was found that metals W and Cu were not able to form a sliding electrical contact with high wear resistance at current density higher 100 A/cm2. The characteristics of the contacts of iron containing metals were slightly better than the contact characteristics of nonferrous metals owing to weaker adhesion. Using X-ray phase analysis, the absence of oxides in the sliding zone of nonferrous metals was shown. This led to their strong wear and low electrical conductivity of contact. In the contact zone of iron-containing samples, the formation of FeO was observed, which made it possible to reduce wear. This means that high electrical conductivity is unattainable in sliding with current collection against molybdenum.

Copper powder spraying is under study: the PMS-1 feedstock copper, the copper that is mechanically milled in a high-energy planetary mill, and the copper that is also spheroidized in a plasma jet. High-density copper coatings are obtained using a CCDS2000 detonation facility. The Vickers microhardness of coatings $$H_{{\mathrm V}_{0.1}}$$ , obtained from feedstock and mechanically milled copper powders, increases from 110 to 160 and from 150 to 185, respectively, and the microhardness of coatings from the spheroidized powder is $$H_{{\mathrm V}_{0.1}}=165$$ . An X-ray phase analysis is carried out, and the resulting data indicate that, during the spraying, the copper oxide is partially reduced.

We synthesized an intermetallic compound Gd2Co7 with Ce2Ni7- and the Er2Co7-type structures. Gd2Co7 with a Ce2Ni7-type structure was stable at 1523 K. The refined lattice parameters were a = 0.5026(1) nm and c = 2.4266(6) nm. The pressure-composition (P–C) isotherm of Ce2Ni7-type Gd2Co7 indicated that reversible hydrogen capacity reached 0.61 H/M (0.76 mass%), and two plateaus were observed in the absorption-desorption process. The crystal structures of both Gd2Co7H2.5 and Gd2Co7H5.5 were determined to be Ce2Ni7-type by X-ray diffraction. Gd2Co7 with Er2Co7-type structure is stable at temperatures below 1473 K. The refined lattice parameters were a = 0.5029(1) nm and c = 3.6403(9) nm. The determined crystal structure of Gd2Co7H2.3 and Gd2Co7H5.4 was Er2Co7-type. The P–C isotherm of Er2Co7-type Gd2Co7 was similar to that of Ce2Ni7-type Gd2Co7. In this study, the P–C isotherms of a polymorphic binary alloy with Ce2Ni7-type and Er2Co7-type structures were obtained for the first time.

The traditional process of alumina production by acid method was to neutralize the aluminum chloride solution obtained by acid leaching for preparing aluminum hydroxide, and then calcined to produce alumina. This process not only had many processes, but also had high energy consumption. In this paper, the properties of alumina prepared by pyrolysis of aluminum chloride solution were studied by chemical composition analysis, XRD and SEM. Thermodynamics of the pyrolysis process was analyzed. The effects of temperature and time on the pyrolysis properties of aluminum chloride solution were investigated. The results showed that it would be completely feasible according to thermodynamic calculation of the pyrolysis reactions of aluminum chloride solution. Meanwhile with the increasing of temperature and pyrolysis time, the residual chlorine content decreased gradually, and the particle size of the product decreased and tended to be uniform. The prolongation of pyrolysis time promoted the pyrolysis process of aluminum chloride solution and contributed to the formation of Al2O3 phase.

Monoclinic zirconium dioxide compositions of formula ZrO2–Al2TiO5 containing 0, 2, and 3.5% Al2TiO5 are studied. The aim of the research is to study the effect of aluminum titanate additives on the parameters of the monoclinic zirconium dioxide crystal lattice and sintering of the resulting product. The formation of a solid solution of aluminum titanate in monoclinic zirconium dioxide is confirmed using SEM and x-ray phase analysis. Sintered products are made from monoclinic zirconium dioxide with aluminum titanate additives as a proof of concept.

Ni-coated mixed powders were synthesized via chemical co-precipitation and hydrogen thermal reduction. Ti(C,N)-based cermets were further fabricated using as-prepared Ni-coated mixed powders successfully. Phase analysis, microstructure characterization, and properties of synthesized powders as well as the as-sintered cermets were investigated using a variety of techniques, including XRD, SEM, EDS. The results exhibited that XRD patterns of present experimental cermets only showed two diffraction peaks that correspond to Ti(C,N) hard phase and nickel binder phase. Also, microstructures of as-sintered cermets were more uniform and finer than those of traditional cermets with the same nominal composition. Meanwhile, present cermets prepared using chemical-coated method had excellent mechanical properties.

The functional refractories used in the continuous casting process of steel are mostly made up of alumina (Al2O3) - carbon (C) system. Graphite is used as the main carbon source because of the properties it offered. Generally, these refractories contain about 30% residual carbon after coking. But the use of high carbon content leads to several disadvantages like carbon pickup by steel, high heat loss and generation of higher extent of COx gases, etc. Hence, the development of low carbon Al2O3-C refractories without conceding any beneficial properties is the challenge to the refractory technologists. Such a challenge is intended in current study with the use of nanocarbon as a complete alternative for graphite. The variation in physical, mechanical and thermo-mechanical properties with variation in amount of nanocarbon in the composition is studied. Phase analysis and microstructural developments are also evaluated along with the oxidation resistance at different temperatures. Because of its high reactivity, nanocarbon helps to form in-situ ceramic phases at much lower temperatures thereby enhances strength and other properties. But the increase in amount of nanocarbon above 2% found to deteriorate the properties.

The possibility of high electrical conductivity of dry sliding electrical contact against molybdenum counterbody was studied. It was found that metals W and Cu were not able to form a sliding electrical contact with high wear resistance at current density higher 100 A/cm2 . The characteristics of the contacts of iron containing metals were slightly better than the contact characteristics of non-ferrous metals due to weaker adhesion. Using X-ray phase analysis, it was shown the absence of oxides in the sliding zone of non-ferrous metals. This led to their strong wear and contact’s low electrical conductivity. In the contact zone of iron containing samples the formation of FeO was observed that made it possible to reduce wear. This means that high electrical conductivity is unattainable in sliding with current collection against molybdenum.

In this research, alumina sol has been synthesized via an inorganic route using inexpensive starting materials including aluminum nitride, deionized water, ammonia, and nitric acid. A clear, homogenous and stable sol was achieved which converted to a soft gel at 60 °C. The physical and microstructural properties of synthesized sol such as pH, particle size, density, solid content, phase analysis, nature of bounds, and thermal behavior were investigated. The pH of the prepared sol was in the range of 3–4, and the solid content was measured by about 6% at the temperature of 1000 °C. Utilizing the SEM micrographs, the average particle size of the dried and calcined sol at 110 °C and 1000 °C were measured less than 20 nm and 40 nm, respectively. XRD patterns of calcined sol at 200, 600, 1200, and 1400 °C revealed the formation of β-alumina (boehmite), γ-alumina, and α-alumina, respectively. Above the temperature of 1200 °C clear and sharp peaks of α-alumina appeared. Also, TG-DSC patterns confirmed the formation of β phase at 200 °C, boehmite into γ transformation at approximately 450 °C, and the alter of γ into α phase at temperatures above 1000 °C.

Investigation of dynamic changes in friction behavior of ultrananocrystalline diamond (UNCD) films is a complex mainly because of the rapid change in chemical composition at the sliding interfaces. To address this issue, for the first time, we report chemical phase analysis of transferfilm using the depth-resolved X-ray photoelectron spectroscopy (XPS) technique. The friction coefficient of the UNCD films was high during the initial run-in regime, but it gradually decreased to an ultralow value after longer sliding cycles at the ambient atmospheric tribo-condition. Depth-resolved XPS analysis showed a higher sp3/sp2 carbon ratio during the initial run-in regime. This ratio decreased with increasing sliding cycles and consequently the friction coefficient decreased. However, a higher value of the friction coefficient throughout the run-in regime persisted at the high-vacuum tribo-condition. In this case, the sp3/sp2 carbon ratio inside the transferfilm was quite high and no considerable changes were observed in the depth-resolved XPS analysis. This investigation confirmed that the dynamic friction behavior in UNCD films was manipulated by the sp3/sp2 carbon ratio inside the transferfilm which showed tribo-atmospheric dependence.

Aluminum alloys based on the Al-Ge-Si system with a germanium content of up to 40 wt.%, promising for the brazing of aluminum alloy AA6082 with the stainless steel AISI 304, were studied. The temperature characteristics and microstructural and mechanical properties of the filler alloys were systematically investigated. Differential scanning calorimetry showed that with an increase in the germanium content from 28.0 to 40.0 wt.%, the liquidus temperature of the filler alloys decreased from 514.8 to 474.3 °C. X-ray diffraction analysis and electron microscopy data showed that the foil of the filler alloys reveals a homogeneous structure. The ingots of the alloys contain two eutectics, the first of which consists of a solid solution of (Al, Ge) with a solid solution of (Ge, Si), and the second consists of a solid solution of (Al, Ge) with a solid solution based on (Ge). When the content of germanium increases from 28.0 to 40.0 wt.%, a separation of the faceted solid solution particles (Ge, Si) and an increase in their number could be observed. Nanohardness measurements showed that the (Ge, Si) and (Ge) solid solutions had similar nanohardness, with values of 11.6 and 10.2 GPa, respectively. Simultaneously, the Al solid solution and the intermetallic Al7Ge2Fe phase exhibited significantly lower nanohardness values of 0.7 and 6.7 GPa, respectively. Brinell hardness measurements showed that the ingots of the filler alloys were sufficiently ductile and had a hardness comparable to that of AA6082, which is used for brazing with AISI 304 stainless steel. The obtained results for the studied ingots and the rapidly quenched foils can be used to predict the forming structure of the seam after brazing and adjusted for diffusion processes occurring between the brazed materials and the studied filler alloys.

The roasting of sulfide ores and concentrates is one of the most important steps in pyrometallurgical metal production from primary raw materials, due to the necessity of excess sulfur removal, present in the virgin material. Pentlandite is one of the main sources for nickel pyrometallurgical production. The knowledge of its reaction mechanism, products distribution during oxidation and reaction kinetics is important for optimizing the production process. Raw pentlandite-bearing ore from the Levack mine (Ontario, Canada) was subjected to oxidative roasting in the air atmosphere. A chemical analysis of the initial sample was conducted according to EDXRF (Energy-Dispersive X-ray Fluorescence) and AAS (Atomic Adsorption Spectrometry) results. The characterization of the initial sample and oxidation products was conducted by an XRD (X-ray Diffraction) and SEM/EDS (Scanning Electron Microscopy with Energy Dispersive Spectrometry) analysis. Thermodynamic calculations, a phase analysis and construction of Kellogg diagrams for Ni-S-O and Fe-S-O systems at 298 K, 773 K, 923 K and 1073 K were used for proposing the theoretical reaction mechanism. A thermal analysis (TG/DTA—Thermogravimetric and Differential Thermal Analyses) was conducted in temperature range 298–1273 K, under a heating rate of 15° min−1. A kinetic analysis was conducted according to the non-isothermal method of Daniels and Borchardt, under a heating rate of 15° min−1. Calculated activation energies of 113 kJ mol−1, 146 kJ mol−1 and 356 kJ mol−1 for three oxidation stages imply that in every examined stage of the oxidation process, temperature is a dominant factor determining the reaction rate.

—By differential thermal analysis and X-ray phase analysis, the reducing properties of special-purpose coke (Reksil) used in the electrothermal production of silicon are compared with those of other solid reducing agents. On the basis of the derivatograms, the kinetic characteristics of the redox processes are calculated.

Separation of aluminum from fine granules of black dross, which is a waste by-product in secondary aluminum production, was investigated. The separation was performed by a multi-stage electrostatic separation method. There are three stages to complete the separation, including preliminary separation, pulse charging enhancement and secondary concentration. Chemical and mineralogical compositions of collection products were analyzed and determined by X-ray diffraction (XRD) and X-ray Fluorescence (XRF). After multistage electrostatic separation, the Al2O3 content of the collection products increases from 50.74% to 69.77%. The mineralogical phase analysis indicates that the final recovery of metallic aluminum phase increases from 8% to 37%, and the aluminum oxide phase increases from 20% to 26%. The research results show the multi-stage electrostatic separation method is effective for recovering of aluminum from fine granules of black dross, and upgrades the black dross to a recoverable material.

In the steel industry, ferromanganese is an important additive. During the production of ferromanganese the ore goes through prereduction and reduction. The prereduction step is very important, as the degree of reduction during ferromanganese is important. Although many investigations have been conducted on different manganese ores, the current study investigated different phases that formed during prereduction when South African ore was used. The ore was mixed with carbon in excess as the reducing agent, and no fluxes were added while CO gas was blown in the furnace. The temperature was varied from 1000°C to 1200°C with 100°C interval. For each temperature, the time varied from 30 min to 90 min with 30 min interval. The ore to carbon ratio was 4:1. After the experiments, the resulting products were subjected to chemical and phase analysis using XRD, XRF and SEM.

A possibility of obtaining bimetallic Pt-W particles in an autoclave at 190°C in an alkaline solution was shown. Structure of the obtained particles was studied by dynamic light scattering and X-ray phase analysis. A possible route for the reduction of platinum and tungsten in the selected conditions to the metallic state with ammonia in statu nascendi was proposed.

The processes occurring in glass-ceramic solders of sapphire-niobium seals, used as current lead-ins in gas-discharge lamps with a discharge in alkali-metal vapor, were studied. The structural changes occurring in the glass-ceramic solder, based on the system of oxides CaO–Al2O3 and CaO–MgO–Al2O3, upon heating to 1600°C with niobium diffusing into the melt, are analyzed on the basis of x-ray phase analysis of the composition and a study of the microhardness.

Friction coefficients and wear resistance are determined, and the x-ray phase composition of experimental samples of obtained material on the basis of silicon and carbon is studied in this paper. Secondary products of the industry were used as initial powder to conduct spark plasma sintering. The composition of burden used for sintering, which was 75% of the mass of silicon and 25% of the mass of graphite (carbon basis), was determined by calculation. Studied samples were obtained by spark plasma sintering method. Based on the analysis of results of the phase composition of the samples obtained by spark plasma sintering method using secondary products of the industry as the initial components, the following conclusions can be made: - It was found that all samples obtained by the method of spark plasma sintering consist of the following phases: The phase of metallic silicon (cubic crystal lattice), the phase of graphite (hexagonal crystal lattice), the phase of silicon carbide with cubic and hexagonal lattice and have a low coefficient of friction; - It was determined that the mass fraction of the silicon carbide phase content is from 20 to 30% depending on the heating temperature; - It was found that the increase in the sintering temperature of the samples have a beneficial effect on the wear intensity of obtained ceramic material; - It was found that from the obtained samples of carbide silicon ceramics the wear resistance of the material increases and the friction coefficient and wear decrease due to an increase in the mass fraction of the carbide phase, that is, a more dense frame is formed. Based on the above, we can say that with an increase in the sintering temperature, the interaction of powder components forms a more stable frame of silicon carbide, which is proved by conducted phase analysis.

The problems of electroerosion phenomena in the diamond grinding zone under the action of additional energy in the form of electric discharges are considered. The erosion effects of electric discharges on the surface of Cu-Sn bonding of diamond grinding wheels are analyzed. Using the methods of X-ray structural and metallographic analysis, the influence of electrical discharges on the bonding is evaluated. Phase analysis indicates changes in the composition and properties of metal bonding with occurrence of new phases that differ from the original structure

The article describes the studies’ results of steels with applied boron-based hardsurfacing overlays. The overlay was done in four different ways. The materials obtained differed in chemical composition, properties and wear resistance. A detailed technical process of surfacing and the surfacing charge composition, which makes it possible to obtain the necessary material, is given. Studies of hardness, macro- and microstructure, chemical and X-ray phase composition of the obtained materials have been carried out. The descriptions of the overlays’ characteristic phases are made and their properties are given. The chemical composition of the obtained overlays has been determined by the emission spectroscopy method. The X-ray phase analysis of the samples has also been carried out and the percentage of the additional modifier introduced into the overlays has been determined. Based on the results of the studies carried out, the conclusions about the optimal method of metal hardening have been drawn.

Bismuth ferrites (BFO) based materials are commonly studied by material science researchers due to their scope in wide range of applications. This applicability arises due to their multiferroic properties and observed transition temperature at various temperatures. Further with suitable doping, the properties have shown interesting modifications. Therefore, structural analysis over a temperature scale is very important for a material scientist to understand the deep-down reasons existing in BFOs. In this study neodymium doped BFOs (Bi1-x NdxFeO3, x = 0.2,0.4,0.6,0.8) are synthesized and characterized with emphasis on their structural analysis with the help of XRD and thermal analysis on their structures with the help of TG-DTA studies.

Thin films for the SiO2–P2O5–CaO–ZnO system were synthesized by the sol-gel method. The compositions and technology for producing thin-film materials on a silicon substrate (model substrate) were developed. The structure of the films was investigated by means of infrared spectroscopy and x-ray phase analysis. It was established that the concentration and contents of the components in the system influence the properties of thin-film materials. The obtained materials are biologically highly active. The composition for obtaining thin-film material with a higher biological activity was determined.

The physical and chemical properties of products from the carbon-thermal reduction of oxide chromo-containing ore raw materials have been investigated. This is necessary to determine the parameters that reduce the loss of Cr in the processing of ore materials and the use of metallized chromium doping additives in steelmaking. It has been determined that the increase in processing temperature from 1,250 K to 1,450 K led to an increase in the manifestation of Cr23C6and (Cr, Fe)7C3. In this case, the diffraction maxima of Cr2O3corresponded to the trend of weakening and, having been treated at 1,450 K, had a residual character. Cr3C2on the diffractograms was only evident after processing at 1,250 K. The phase of the metallic Cr was traced in the samples after processing at 1,350 K and 1,450 K with the increased intensity of manifestation when the heating temperature rose. It has been determined that the microstructure of reduction products is heterogeneous with the presence of particles of different sizes and chemical compositions. The increase in the reduction temperature from 1,250 K to 1,350 K and 1,450 K and the development of reduction processes were accompanied by particle sintering with the formation of a spongy microstructure. We have detected regions that characterized inclusions and the phases where Cr content amounted to 65.10 % by weight, Fe ‒ to 16.13 % by weight. Some local areas with particles with a relatively high content of ore impurities and carbon have also been found. It follows from the results of our study that the most acceptable temperature for reduction is 1,450 K. In this case, the reduction is ensured with a predominance in the phase composition of the metal Cr and carbides (Cr, Fe)7C3and Cr23C6relative to the oxide component of Cr2O3. In this case, the lower residual carbon content was due to the higher efficiency of the reducer compared to other temperature regimes. The spongy microstructure allows for a faster dissolution compared to standard ferroalloys, thereby reducing the duration of smelting

Electrophoretic nuclear magnetic resonance (eNMR) is a powerful tool in studies of nonaqueous electrolytes, such as ionic liquids. It delivers electrophoretic mobilities of the ionic constituents and thus sheds light on ion correlations. In applications of liquid electrolytes, uncharged additives are often employed, detectable via 1 H NMR. Characterizing their mobility and coordination to charged entities is desirable; however, it is often hampered by small intensities and 1 H signals overlapping with major constituents of the electrolyte. In this work, we evaluate methods of phase analysis of overlapping resonances to yield electrophoretic mobilities even for minor constituents. We use phase-sensitive spectral deconvolution via a set of Lorentz distributions for the investigation of the migration behavior of additives in two different ionic liquid-based lithium salt electrolytes. For vinylene carbonate as an additive, no field-induced drift is observed; thus, its coordination to the Li+ ion does not induce a correlated drift with Li+ . On the other hand, in a solvate ionic liquid with tetraglyme (G4) as an additive, a correlated migration of tetraglyme with lithium as a complex solvate cation is directly proven by eNMR. The phase evaluation procedure of superimposed resonances thus broadens the applicability of eNMR to application-relevant complex electrolyte mixtures containing neutral additives with superimposed resonances.

Strain within nanomaterials plays a crucial role in defining their physical and chemical properties. Geometrical phase analysis (GPA) was widely used to investigate deformation within nanomaterials. The traditional GPA method using geometric phases of two lattice fringes provides two-dimensional strain mapping, which is inapplicable to nanomaterials viewed along high-index zone axis. Herein using silicon nanoplate embedded in Si0.5Ge0.5 matrix as a test object, we illustrate a GPA method using single lattice fringes. The availability of this GPA method was testified by comparison with traditional GPA method. This work presents an opportunity to extend application of the GPA method.

The study of phase transformations in the system” lead-containing dust – sulfur ” is actual, as in many pyrometallurgical processes lead-containing dust is formed. The accumulation of such industrial waste causes ecologically stress on the environment. The sulfur is select as a sulfiding agent due to the problem of its utilization in the oil industry. The article covers the possibility of lead dust sulfiding with technical sulphur. Thermal and x-ray phase analysis of mixtures of lead dust and elemental sulfur in various ratios was carried out. Thermal analysis was performed on a Q-1000/D derivatives without air access, which was achieved by blocking crucible with the analyzed samples by aluminum oxide, in the temperature range 20-1000 ° C, heating mode – dynamic (dT/dt = 10 deg/min), reference substance – calcined Al2O3. X-ray diffraction analysis was performed on an automated diffractometer DRON-4 with CuКa-radiation and β-filter. In the studied system, the main temperature intervals, wherein sulfur actively reveal itself, are 60-220 and 220-360 °C. The state of the system beyond 450 °C is clear from the physical properties of the lead dust. Rising of sulfur concentration increases the visibility of the peak on the DTA-curve associated with polymorphic transformation of lead oxy-sulfates and activation of sulfide formation processes. The increase in the intensity of the effects of sulfur direct interaction with the components of the charge reflects the difference in sulfur concentrations in the compared samples. On the other hand, the increase of sulfur content in the composition of the sample leads to some attenuation of the physical properties (melting) of lead oxy-sulfates. Thus, the increase of the sulfur content in the charge more strongly stimulates the development of sulfidization process in the system, which takes place within 140-300 °C. Within the same next stage of thermal manifestation, sulfide formation in the system and activation of the lead compound interaction is directly related to sulfur. The scientific and practical significance of the investigation is in the possibility of the use of technical sulfur, waste oil industry for sulfiding lead dust.

The mechanochemical reduction of copper (I and II) oxides by magnesium is studied by means of X-ray phase analysis, electron microscopy, and EDS elemental analysis. The conditions for separating copper particles from other products and protecting copper from oxidation during storage are determined. The sizes of the obtained aggregated particles of reduced copper (~100 nm) are estimated via scanning electron microscopy.

The interfaces of a physical-vapor deposited (PVD)-TiN electrode with atomic-layer deposited (ALD) HfO2 layers were studied using photoelectron spectroscopy with high kinetic energies of photoelectrons enabling nondestructive in-depth chemical profiling and phase analysis. Our results reveal the presence of only TiNxOy at the TiN/ALD-HfO2 interface with no measurable traces of the TiO2 phase. By contrast, the interface formed by ALD of HfO2 on top of PVD TiN contains both TiO2 and TiNxOy compounds and may be compared to an HfO2/TiN interface with intentional ALD TiO2 interlayer (IL) formation prior to HfO2 growth. Pre-growth of ALD Al2O3 IL drastically reduces the TiO2 and TiNxOy amounts present at the HfO2/TiN interface, which can be ascribed to oxygen scavenging from the initially oxidized TiN surface by energetically more favorable Al-O bonds. The present study demonstrates that the amount of TiO2 phase can be effectively controlled, i.e., increased or decreased, during the ALD process enabling engineering of vacancy-mediated processes. ispartof: PHYSICAL CHEMISTRY CHEMICAL PHYSICS vol:20 issue:44 pages:27975-27982 ispartof: location:England status: published

The study has revealed the regularities of the effect produced by increasing the content of scale of steel 12Cr18Ni10Ti in the charge from 5 to 75 mass % on the contents of the products of carbon thermal reduction of oxide waste of corrosion-resistant steels. The concentration of Ni is increased from 0.8 to 7.0 mass % when the Cr content ranges from 15.9 to 17.1 mass %. The concentration of Cr in the extraction products within the range of 16.1–17.1 mass% is provided with the content of scale of 95Cr18 steel in the charge in the range from 5 to 55 mass %. It has been found that metallization products mainly consist of a solid solution of alloying elements in α-Fe. Fe 3 O 4 , Fe 3 C, and Fe 2 C were also identified. The microstructure of the extraction products is spongy and disordered. The particles are sintered, with varying Cr and Ni contents in the ranges of 7.47 to 18.03 mass % and 2.97–10.40 mass %, respectively. The study has helped achieve environmentally safe conditions for solid-phase extraction of chrome and nickel containing industrial wastes from the production of corrosion-resistant steels with the return of the alloyed product to the welding industry

This study aims to investigate the role of graphene on wear and corrosion behaviors of pure magnesium. Magnesium/Graphene Nanoparticle (GNP) composites were fabricated via semi powder metallurgy method with a different content of graphene (0.1, 0.25 and 0.5 wt%). The effect of graphene in pure magnesium was examined by hardness, wear and corrosion tests. Microstructural and phase analysis were carried out by Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD) analysis. Experimental results revealed that, hardness values increased with the addition of graphene. There was a same trend in wear behaviors with increase of graphene rate. The best wear performance was belonging to the 0.50 wt% graphene/mg composite under load of 10N. So improvement of wear properties was achieved using graphene as reinforcement. According to the microstructural evolution, the uniform distribution was achieved for all samples but partially agglomeration could be seen in Mg-0.50 wt% graphene. Compared to the pure magnesium, corrosion performance was affected negatively in graphene reinforced composites.

The majority of primary pyrometallurgical copper making processes involve the formation of two immiscible liquid phases, i.e., matte product and the slag phase. There are significant gaps and discrepancies in the phase equilibria data of the slag and the matte systems due to issues and difficulties in performing the experiments and phase analysis. The present study aims to develop an improved experimental methodology for accurate characterisation of gas/slag/matte/tridymite equilibria in the Cu-Fe-O-S-Si system under controlled atmospheres. The experiments involve high-temperature equilibration of synthetic mixtures on silica substrates in CO/CO2/SO2/Ar atmospheres, rapid quenching of samples into water, and direct composition measurement of the equilibrium phases using Electron Probe X-ray Microanalysis (EPMA). A four-point-test procedure was applied to ensure the achievement of equilibrium, which included the following: (i) investigation of equilibration as a function of time, (ii) assessment of phase homogeneity, (iii) confirmation of equilibrium by approaching from different starting conditions, and (iv) systematic analysis of the reactions specific to the system. An iterative improved experimental methodology was developed using this four-point-test approach to characterize the complex multi-component, multi-phase equilibria with high accuracy and precision. The present study is a part of a broader overall research program on the characterisation of the multi-component (Cu-Fe-O-S-Si-Al-Ca-Mg), multi-phase (gas/slag/matte/metal/solids) systems with minor elements (Pb, Zn, As, Bi, Sn, Sb, Ag, and Au).

The segregation of the elements during solidification and the direct formation of destructive phases such as Laves from the liquid, result in in-homogeneity of the cast structure and degradation of mechanical properties. Homogenization heat treatment is one of the ways to eliminate destructive Laves from the cast structure of superalloys such as 718Plus. The collected data presents the effect of homogenization treatment conditions on the cast structure, hardness, and tensile properties of the alloy 718Plus in the presence of boron and zirconium additives. For this purpose, five alloys with different contents of boron and zirconium were cast by VIM/VAR process and then were homogenized at various conditions. The microstructural investigation by OM and SEM and phase analysis by XRD were done and then hardness and tensile tests were performed on the homogenized alloys. Keywords: Homogenization, Boron, Zirconium, 718Plus, Strength, Ductility

New La/Zn substituted strontium ferrites Sr(2 −x)La x [Fe(2 − x)Zn x ]O5, (0 ≤ x ≤ 0.3) with brownmillerite- type structure are obtained and studied via X-ray phase analysis and Mossbauer spectroscopy. Depending on the conditions of synthesis, substituting Zn2+ cations can either mainly occupy tetrahedral positions in a brownmillerite structure, or be uniformly distributed between the tetrahedral and octahedral positions. It is shown that they are reversibly oxidized by atmospheric oxygen at elevated temperatures.

In Poland, researchers have a very strong interest in archaeometallurgy, which, as presented in classical works, focuses on dating artefacts from the prehistoric and early medieval periods in the form of cast iron and copper castings. This study, extending the current knowledge, presents the results of a microstructure investigation into the findings from the Modern era dating back to the late Middle Ages. The investigated material was an object in the form of a heavy solid copper block weighing several kilograms that was excavated by a team of Polish archaeologists working under the direction of Ms Iwona Młodkowska-Przepiórowska during works on the marketplace in the city of Czestochowa during the summer of 2009. Pre-dating of the material indicates the period of the seventeenth century AD. The solid copper block was delivered in the form of a part shaped like a bell, named later in this work as a “kettlebell”. To determine the microstructure, the structural components, chemical composition, and homogeneity, as well as additives and impurities, investigations were carried out using light microscopy, scanning electron microscopy including analysis of the chemical composition performed in micro-areas, and qualitative X-ray phase analysis in order to investigate the phase composition. Interpretation of the analytical results of the material’s microstructure will also help modify and/or develop new methodological assumptions to investigate further archaeometallurgical exhibits, throwing new light on and expanding the area of knowledge of the use and processing of seventeenth-century metallic materials.

Objectives: This study aimed to evaluate the chemical and biological properties of fast-set white mineral trioxide aggregate (FS WMTA), which was WMTA combined with calcium chloride dihydrate (CaCl2·2H2O), compared to that of WMTA. Materials and Methods: Surface morphology, elemental, and phase analysis were examined using scanning electron microscope (SEM), energy dispersive X-ray microanalysis (EDX), and X-ray diffraction (XRD), respectively. The cytotoxicity and cell attachment properties were evaluated on human periodontal ligament fibroblasts (HPLFs) using methyl-thiazol-diphenyltetrazolium (MTT) assay and under SEM after 24 and 72 hours, respectively. Results: Results showed that the addition of CaCl2·2H2O to WMTA affected the surface morphology and chemical composition. Although FS WMTA exhibited a non-cytotoxic profile, the cell viability values of this combination were lesser than WMTA, and the difference was significant in 7 out of 10 concentrations at the 2 time intervals (p < 0.05). HPLFs adhered over the surface of WMTA and at the interface, after 24 hours of incubation. After 72 hours, there were increased numbers of HPLFs with prominent cytoplasmic processes. Similar findings were observed with FS WMTA, but the cells were not as confluent as with WMTA. Conclusions: The addition of CaCl2·2H2O to WMTA affected its chemical properties. The favorable biological profile of FS WMTA towards HPLFs may have a potential impact on its clinical application for repair of perforation defects.

Structural, spectral, and thermodynamic characteristics of complex amidoboranes M2[M1(NH2BH3)4] (M1 = Al, Ga; M2 = Li, Na, K, Rb, Cs) were calculated by the B3LYP/def2-SVPD quantum-chemical method. The procedure for the synthesis of these compounds by reactions of alkali metal amidoboranes with aluminum and gallium chlorides was suggested and experimentally tested. Reaction products were characterized by the NMR and IR spectroscopy and X-ray phase analysis.

The association between left ventricular (LV) dyssynchrony parameters, given by phase analysis of gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI), and acquisition orbits is unclear. The aim of this study was to assess the dependence of LV dyssynchrony parameters on acquisition orbits. Ninety-nine patients who underwent 201Tl-gated SPECT MPI were categorized into minor hypoperfusion or major hypoperfusion groups. Forty-four patients who underwent 99mTc-tetrofosmin-gated SPECT MPI were categorized into minor hypoperfusion or major hypoperfusion groups. The major hypoperfusion group with 201Tl was divided into inferior or non-inferior wall hypoperfusion subgroups, and anteroseptal or non-anteroseptal wall hypoperfusion subgroups. Gated SPECT MPI data over a 360° acquisition orbit (360° images) and a 180° acquisition orbit (180° images) were reconstructed, and histogram bandwidth (HBW) and phase standard deviation (PSD) were compared. Between 360° and 180° images with 201Tl, there were significant differences in HBW and PSD both globally (HBW 34.8 ± 16.6 vs. 29.1 ± 10.2; PSD 8.8 ± 4.9 vs. 7.0 ± 2.3, p

X-ray diffraction phase analysis of samples performed on a DRON-6 diffractometer has shown that the processes of CaWO4 transition to WC and W2C had the highest probability in the temperature range of 1,173–1,473 K. The end-product CaWO4, thermally treated with carbon, was represented by carbon in oxycarbide and carbide phases. The processes of tungsten reduction from its oxides through the phases of formation of tungsten carbide and oxygen compounds (higher and lower) and finally tungsten metal were shown. Basic chemical and phase transformations occurred within the temperature range of 300–1,800 K. This opens the prospect of producing tungsten as an alloying material without formation of liquid phases in a heterogeneous system and enables production of tungsten based alloying material at relatively low temperatures which significantly reduces power consumption. Qualitative and quantitative composition of charge materials for laboratory studies and industrial tests in a form of briquettes for metallization of tungsten-containing compounds in a furnace with induction heating was presented. The mechanism of phase and structural transformations occurring in reduction of tungsten from scheelite concentrates in the temperature range of 1,273–1,473 K and microanalysis of samples of chemical transformations were studied. A furnace unit with induction heating in which industrial tests were performed in stages was schematically shown.The tests have shown that a 1.3 times sample weight reduction and a 23 % specific density reduction occurred in the process of heat treatment of the samples based on scheelite concentrate.Several batches of spongy tungsten instead of standard ferrotungsten were produced and tested in smelting high speed steels. Advantages of the new technology of tungsten metallization from a scheelite concentrate and positive efficiency of using the new material in special metallurgy were shown., Виконаний рентгеноструктурний фазовий аналіз зразків на дифрактометрі «ДРОН-6» показав, що найбільшу ймовірність в інтервалі температур 1173–1473 K мають процеси переходу CaWO4 в WC і W2С. Кінцевий продукт вуглеродотерміі CaWO4 представлений вуглецем в оксикарбідних і карбідних фазах. Показані процеси відновлення вольфраму з його оксидів через фази утворення карбідних сполук вольфраму, кисневих сполук (вищих і нижчих), і тільки потім вольфраму металевого. Основні хімічні та фазові перетворення протікають в межах температурного інтервалу 300–1800 K. Це відкриває перспективу виробництва вольфраму як легуючого матеріалу без утворення рідких фаз в гетерогенній системі та дає можливість виробляти легуючий матеріал на основі вольфраму при відносно невисоких температурах, що значно скорочує енерговитрати. Наведено якісний й кількісний склад шихтових матеріалів для лабораторних досліджень та промислових випробувань брикетів для металізації вольфрамовмісних сполук у шахтній печі з індукційним нагрівом. Досліджено механізм фазових структурних перетворень за відновлення W із шеєлітового концентрату в діапазоні температур 1273–1473 K і мікроаналіз зразків хімічних перетворень. Схематично показаний пічний агрегат із індукційним нагрівом, у якому поетапно виконані промислові випробування.Проведені випробування показали, що в процесі теплової обробки зразків на основі шеєлітового концентрату їх маса зменшується в 1,3 рази, а питома щільність знижується на 23 %.Було вироблено партії губчастого вольфраму, який було випробувано під час виплавки швидкорізальних сталей взамін стандартного феровольфраму. Показані переваги нової технології металізації W із шеєлітового концентрату та позитивна ефективність використання нового матеріалу в спеціальній металургії, Выполненный рентгеноструктурный фазовый анализ образцов на дифрактометре «ДРОН-6», показал, что наибольшую вероятность в интервале температур 1173–1473 K имеют процессы перехода CaWO4 в WC и W2С. Конечный продукт углеродотермии CaWO4 представлен углеродом в оксикарбидных и карбидных фазах. Показаны процессы восстановления вольфрама из его оксидов через фазы образования карбидных соединений вольфрама, кислородных соединений (высших и низших), и только потом вольфрама металлического. Основные химические и фазовые преобразования протекают в пределах температурного интервала 300–1800 K. Это открывает перспективу применения вольфрама как легирующего материала без образования жидких фаз в гетерогенной системе и дает возможность производить легирующий материал на основе вольфрама при относительно невысоких температурах, что значительно сокращает энергозатраты.Приведены качественный и количественный состав шихтовых материалов для лабораторных исследований и промышленных испытаний брикетов для металлизации вольфрамосодержащих соединений шахтной печи с индукционным нагревом. Исследован механизм фазовых структурных преобразований при восстановлении W с шеелитового концентрата в диапазоне температур 1273–1473 K и микроанализ образцов химических превращений. Схематично показан печной агрегат непрерывного действия с индукционным нагревом, в котором поэтапно выполнены промышленные испытания.Проведенные испытания показали, что в процессе тепловой обработки образцов на основе шеелитового концентрата их масса уменьшается в 1,3 раза, а удельная плотность снижается на 23 %.Для определения технико-экономических показателей произведены партии губчатого вольфрама, которые испытаны при выплавке быстрорежущих сталей взамен стандартного ферровольфрама. Показаны преимущества новой технологии металлизации W с шеелитового концентрата и положительная эффективность использования нового материала в специальной металлургии

The article deals with development of the dust waste pelletizing technology for the silicon production industry in order to minimize environmental risks electron microscopy, gravimetric, chemical, X-ray phase analysis methods were used. The results show that silicon dust containing 86% of SiO 2 should be used as an additional source of raw materials for silicon production using the workmanship method which reduces the environmental load of the nearby region and improves working conditions. The silicon production diagram with an additional pelletizing stage was developed.