Raster Electron Microscopy Research Articles

IMPROVEMENT OF THE ALLOY STRUCTURE OF THE Ni-Cr-Со-W-Mo-Al-Ti-C SYSTEM

Purpose. Establishing the specifics of the influence of alloying elements on the formation of carbides in the structure, their shape and the possibility of separating TLC phases for the system of the Ni-Cr-Co-W-Mo-Al-Ti-C type using the CALPHAD calculation method of prediction in comparison with data obtained by the method of raster electron microscopy. Research methods. The results of experimental and calculated data, formed on the basis of experimental and results taken from open sources, are presented. The chemical composition was determined on a REM-106I scanning electron microscope equipped with an energy dispersive analysis. Experimental values were processed by the method of least squares with obtaining correlation dependencies of the “parameter-property” type and establishing mathematical equations of regression models that optimally describe these dependencies. Results. It was established that when the concentration of titanium is more than 4 % and molybdenum is more than 6 % and 15 % chromium, the formation of TSC phases (Р, s and m- phases) is possible, which reduce the operational properties of the alloy. It was found that when the alloy contains more than 25 % chromium, a solid chromium-based solution is formed, which reduces the properties of the alloy (mechanical and corrosion). It is shown that the obtained dependences correspond to reality and coincide with experimental data at the level of 10 %. Scientific novelty. Obtained dependences of the influence of alloying elements on the chemical composition of carbides will allow predicting properties without conducting experiments. It was established that changes in the course of dependencies are closely correlated with the processes occurring in the structure of alloys. Practical value. The obtained dependencies can be used both for the development of new heat-resistant alloys and for the improvement of the compositions of industrial alloys.

Sausage meat product enriched by jida

The development strategy aimed at creating the independence of the use of our raw materials by domestic meat producers is currently achieving the following goals: building modern production facilities and introducing new primary and processing technologies; expanding the assortment of meat products. The scientific research works carried out during the development of technology for the production of meat products by replacing a certain amount of beef or chicken with vegetable raw materials are important. Production of meat products based on these raw materials allows effective use of local raw materials, production of functional products and expansion of the range of meat products. The purpose of the study is to consider the features of the production technology of sausage meat product enriched with jida. The article presents the processing of the meat product production technology by enriching its composition with raw materials of vegetable origin - jida powder and the analysis of the mineral content of the finished product. The research work was carried out at the "Food Engineering" department of the M. Auezov South Kazakhstan University and at the "Construction and Biochemical Materials" regional test laboratory of engineering profile. Raster electron microscope (REM) and inductively coupled plasma mass spectrometry (ICP-MS) methods were used to determine the amount of mineral substances in meat products - sausage. The specialty of this work is the technology of product production using vegetable raw materials to enrich the content of meat products - sausages with minerals. Vegetable raw material - jida powder, by using it in the production of functional meat products, enriches the mineral content of meat products, and also by replacing a small part of meat raw materials, contributes to increasing the yield of the product. Jida powder is a vegetable raw material that is soluble in cold water and rich in dietary fiber, vitamin C, flavonoids and organic acids and does not cause losses in the production of food product. Jida powder production technology consists of: cleaning berries from dust and impuri[1]ties (passing them through a sorting fan); crushing (optimal duration of berry crushing in the IV-1 crusher τ= 52-65 sec, rotation speed of the working body 12000 rpm); drying (dry in the sun for fruits with a high sugar content).

Multifunctional Nanocomposites in B4C-Tic-Tib2-Sic-BN-Al2O3-Sialon-C Carbon Fiber System for Armor Fillets, Turbine Discs and Wings, High-Temperature Wear Resistant Nodes

Goal - to receive on first stage β - SIALON containing nanocomposites by reactive sintering method at 14000C, with nitrogen pro-cess from origin composition in TiC-BN-SiC-B4C-Si-Al-Al2O3 (nanopowder) system. By using this method of synthesis, it became possible to receive nanocomposites with different percentages of β - SIALON. Our task was to study the phase composition of re-ceived consolidated materials in the TiC-TiB2-BN-SiC-B4C-β-SiAlON-Al2O3 (nanopowder-400nm.) system. Method. The obtained mass was grounded in an attritor and the consolidated composite was obtained by hot pressing at 16200C during 40 minutes, with glass perlite (Armenia) dope 2 mass%, delaying at final temperature for 8 min, under 30 MPa pressure and vacuum – 10-3 Pa. Perlite from Aragatc contained 96 mas. % glass. To study the phase composition of the composites, we conducted an X-ray structural analysis on the DRON-3 device. And to study the microstructure, we conducted research on an optical microscope -AC100 and a raster electron microscope “Nanolab 7” of the company "OPTON”. The values of the electrical parameters of the studied composites were calculated on the basis of the ob-tained "lgp- t" dependence. We have studied mechanical properties. Result. In TiC-TiB2-BN-SiC-B4C- β-SiAlON-Al2O3 – C Carbon Fiber system we obtained nanocomposites with high mechanical proper-ties. The advantage of this method is that compounds, which are newly formed thanks to interaction going on at thermal treat-ment: Si3N4, Si, AlN are active, which contributes to β-SiALON formation at relatively low temperature, at 1300-13500C. It is evi-dent that inculcation of ALN in crystal skeleton of ß-Si3N4 is easier since at this temperature interval crystal skeleton of Si3N4 is still in the process of formation. ß-SiAlON was formed at 14500C. Part of boron carbide was transformed into boron nitride in ni-trogen environment and in titanium diboride, which in the case of both composites is in small quantities. Conclusion. The phase composition of the obtained composite provides high physical-technical and performance properties of these nanocomposites. Compression strength-2198 MPa, Bending strength-271 MPa, Thermal expansion coefficient a20-700-3.8 10-6 0C.

EFFECT OF DEFECTIVE MICROSTRUCTURE ON THE VALUE AND NATURE OF DISTRIBUTION OF RESIDUAL MACRO-STRESSES ON THE STEEL COUPLING OF THE TUBING

The work analyzes the influence of certain types of metal microstructure defects on the value and nature of distribution of the active residual macro-stresses of the σ in the tubing sleeve. The tubing coupling was made of pre-eutectoid steel, and to improve corrosion resistance, a bainite structure was formed in it. As defects of the metal microstructure, the most common cases in the manufacture of a coupling were considered, such as the structural gradient of the formation of constituent phases (upper and lower bainite, martensite tempering, martensite, etc.) along the thickness of the tubing wall, as well as non-metallic inclusions and pores in the material wall. To assess the residual macrostresses on the selected coupling surface, a non-destructive X-ray scattering method modified by the authors was used. At the same time, the modernization of this method consisted in the use of a micro-X-ray parallel beam (diameter 0.5 mm) in estimating the σ value, in measuring the spectrum of reflexes at inclined surveys at given coordinates (pitch 1.0 mm) for different directions of the φ plane, in determining the value of macro-stresses at each point and constructing their surface distribution with superimposed power lines. In order to take into account the anisotropy of the acting residual macro-stresses of the σφ on the analyzed surface of the coupling, in the measurements of the reflex (222), the sample was rotated about an axis perpendicular to the analysis plane. As a result of applying the modified macro stress estimation approach for the initial tubing sleeve having no process defects, it is found that the distribution of residual macro stresses in the longitudinal section of the wall is symmetrical. It is shown that residual compressive-type macro stresses of minus 341 MPa are formed in the inner part of the tubing coupling wall, and the tensile type — with the value of plus 347 MPa acts on the outer side of the coupling wall, the absence of macro stresses is detected in the middle part of the material wall. It has been shown that the presence of a structural gradient, i.e. the presence of martensitic plates in the near-surface layers of the coupling with a content of about 12 %, increases the active residual macro-stresses in these areas by more than 1.3 times. It was found that the presence of pores and non-metallic inclusions in the near-surface layers concentrated on the thickness of 170 μm of the coupling wall increases the residual macro stresses 1.6 times from the outside and 1.4 times from the inside of the wall. It has been shown that increased pore size and increased pore content, which are analyzed by raster electron microscopy, are factors in the increase of macro stresses from the outside of the coupling wall.

Применение метода тринарной дискретизации для анализа структурного распределения углерода в графеносодержащем шунгите

Using the high-permission raster electron microscopy on nano-level the structure distribution of carbon in natural graphene-containing shungite applied for manufacturing adsorbing surfaces is investigated. The analysis is executed in specimens with specific carbon containing about 80-97% and specific conductivity from 2200 to 8600 Sm/m. The results of measuring were the cards of carbon distribution along the specimen surface. It was investigated four specimens and in each specimen was copied five cards in different its points, as a result – twenty cards. It is found the presence on the cards the graphene packets and long graphene ribbons and also domains without clear graphene-similar structure. For the analysis of local carbon distribution, it is proposed the discretization method which consist of applying on the card plane the grid with square cells and following analysis of regularity graphene layers by each cell. It is found three levels of structure regularization: high, middle and low. For the high level it is typical the regular periodic distribution of graphene layers along the whole square of cell, for middle – explosive character of graphene layers, for low – absence of graphene layers along the whole cell. For individual characteristics of each specimen, it is proposed the concept of order degree which supposed the relative number cells in three levels which is averaged on all its cards. It is found that in typical case the high degree of order presents on 35,4% of card area, middle in 47,3% and low in 17,3% of the same area. By way of possible course of distinction in order level is proposed the specific geological origin of specimens from different depositions.

Применение метода трехуровневой дискретизации для анализа связи между структурой и удельной проводимостью графеносодержащего шунгита

The correlation between structure configuration of carbon distribution of graphene-contained shungite and its specific electrical conductivity is investigated. The four shungite specimens from different natural depositions are investigated. The carbon structure configuration is investigated by high-permission raster electron microscopy. As a result, there was found cards of graphene layers, graphene packets and graphene ribbons along the plane of specimen surface. The specific electrical conductivity was merit be the four-contact method. On each specimen was found five cards in different its points as a whole – twenty cards. For the analysis of carbon local distribution, the descretization by three levels method was used. This method consists of applying on the card plane the grid with square cells and following analysis of regularity graphene layers by each cell. It is found three levels of order regularity structure: high, middle and low which distinguished by the number and length of graphene layers inside of cell. By averaging along all cards of present specimen for each specimen was found the own numerical characteristic which describes the carbon distribution structure. As a most important parameters were selected the averaged meaning of order degree and inversed value of square deflection from this value. It was found that the dependence of inverted value on specimen from the specimen number has the same character as the dependence on specific conductivity form the same number. As a result of investigations, it was proposed that the specific conductivity of shungite specimen may be found from statistical analysis of carbon space distribution cards which are found by the high-permission raster electron microscopy. It was proposed the algorithm of founding conductivity by analysis carbon configuration cards consisted from 16 successive steps which started from the founding the total combination of cards with the aid of electron microscope and finished by obtaining the electric conductivity value.

Determining the pattern of direction and distribution of intermetallic phase in the eutectic of the weld material after electron-beam welding of titanium and niobium alloys

This paper reports a study whose object was material of the weld. The nature of changes in the microstructure of the weld material, which are caused by changes in the supplied energy, alloying elements and heat removal from the melt area, was investigated. Welding was performed with an electron beam at Uacc=60 kV, Ieb=90 mA, with an elliptical sweep of 3×4 mm. The speed of electron beam movement veb was varied from 7 to 15 mm·s-1. The temperature of the experimental welded samples T0 was varied from 300 K to 673 K. Ti-TiB alloy (a microcomposite alloy with reinforcing TiB fibers) was welded with Ti-TiB alloys, T110, and with niobium. One of the tasks of welding this alloy was to preserve and optimize the structure of this type in the weld. Grinding of boride fibers, loss of their initial orientation, and formation of a dendritic or cellular microstructure was observed in the weld. Using the methods of raster electron microscopy and micro-X-ray spectral analysis, the microstructure of the weld material was investigated and the dimensional characteristics of TiB fibers under different welding conditions were determined. The analysis of changes in the microstructure of the weld material, the average length ᶏ and the thickness ȩ of the boride fibers in the material of the joints made at different velocities of electron beam movement and initial temperatures T0 was carried out. It was established that the growth of the ratio ȩ/ᶏ from 0.04–0.07 to 0.1–0.27 is accompanied by significant changes in the microstructure and the mechanism of formation of eutectic phases. It is shown that the process that determines the formation of the microstructure of the weld material was the eutectic breakdown with the determining influence of the temperature gradient, crystallization rate, supercooling, concentration inhomogeneities, and alloying impurities.

Development of the Recycling of Alloyed Metallurgical Waste: Features of Phase and Structural Transformations

The features of structural and phase transformations during the processing of alloyed metallurgical wastes using reduction smelting are determined herein. This is necessary in order to determine the technological parameters of the melting process that ensure the reduction in the losses of alloying components. The use of X-ray phase analysis in combination with the methods of raster electron microscopy and X-ray microanalysis ensured the identification of the microstructure features and the chemical composition of individual phases and inclusions in the metal. Our study identified new technological aspects of high-alloyed technogenic waste processing using reduction smelting. The obtained parameters of the resource-saving alloying compound provide the possibility to replace parts of the standard ferroalloys in steelmaking processes.

Obtaining high-strength carbon fiber based on polyphenylene sulfide by ATL method with laser heating

The method of manufacturing high-strength structural carbon fiber from toupreg based on PPS-214 grade polyphenylene sulfide (Fortron, Germany) and AS4 high-strength carbon fiber (Hexcel, USA) using a promising ATL-technology (Automated Tape Laying) with laser heating is considered. The technology was adapted for the material under study, laboratory models in the form of plates were made, physical and mechanical tests of laboratory samples were carried out. The quality of the binder distribution and the presence of defects were assessed by raster electron microscopy. The influence of the reinforcement, pressing and vacuum heat treatment schemes on improving the mechanical properties of the studied carbon fiber was investigated. It has been found that the samples subjected to vacuum heat treatment have higher mechanical properties due to an increase in the adhesion of the toupreg tapes to each other and the removal of discontinuities formed during the calculation. The value of the ultimate strength at interlayer shear of samples made using a parallel-diagonal scheme increases by 108%, at bending by 370% and by 65% at compression.By processing the toupregs by the ATL with laser heating and subsequent thermal treatment of the products, it is possible to obtain high-strength structural materials with improved physical and mechanical properties, as well as high repeatability and equality of properties throughout the area of the products, even using complex reinforcement schemes.

Layer thickness characterization of Faraday cup fast ion loss detectors.

Faraday cup fast ion loss detectors have attractive properties for fusion applications, as they can measure wide ranges of energy, are intrinsically neutron-hardened, and can be packaged in very small form factors. The latter allows them to be installed as arrays, offering opportunities to decouple fast ion loss location and magnitude in fully three-dimensional magnetic fields. In this work, we characterize the layer thicknesses of detector prototypes using spectral reflectance measurements, confocal laser scanning microscopy, as well as raster electron microscopy with a focused ion beam. We find that the measured layer thicknesses agree well enough with the specification to allow for accurate measurements. The as-manufactured heights are on the high side, increasing reliability. The data presented here further sets the basis for future optimizations in manufacturing.

Glowing selenates: novel alkaline earth nanoparticles.

Up to now, no selenate nanoparticles have been described even though much research has been done on respective oxidic compounds such as sulfates and phosphates. For the first time, alkaline earth selenates of the composition MSeO4 (M = Ca, Sr, Ba) were synthesized as nanoparticles or nanorods as described in this publication. For this purpose, a micro emulsion method was applied using CTAB as a surfactant. Using X-ray diffraction measurements (XRD) phase purity of the materials could be proven. Furthermore, the nanoparticles were analyzed by raster electron microscopy (REM) and dynamic light scattering (DLS) measurements. Finally, the products were doped with small amounts of Eu3+ to obtain luminescent materials. Successful doping was demonstrated by luminescence investigations in the region of 18 000 to 14 000 cm-1 (550-715 nm). Incorporation of Eu3+ led to strong red-emitting nanoparticles. Low temperature measurements at 10 K allowed conclusions about the site symmetry of Eu3+ ions located on the alkaline earth sites.

Increasing the level of safety and occupational hygiene during the ecologically oriented processing of leather industry waste and the peculiarities of their microstructure

The article is devoted to the study of the peculiarities of the microstructure of cinders from leather industry waste. This is necessary for the use of the obtained material as a chromium-containing raw material for the production of alloying additives by aluminothermic melting. To achieve this goal, a complex of the latest research methods was applied using raster electron microscopy together with X-ray microanalysis to determine the chemical composition of the target areas of the surface of the samples. Thanks to the successfully conducted stages of research, significant results were obtained with the determination that the cinder microstructure was disordered, porous and consisted of separated particles of different shapes and sizes. The oxide nature of the majority of the components is due to the detection of oxygen in the analysis areas in the range of 14.04-25.12 %wt. In the studied areas, the chromium content was at a relatively high level — from 59.49 %wt. up to 74.64 %wt. Of the refractory elements, vanadium was also present in the amount of 0.18-0.29 %wt. The iron content ranged from 0.41 to 0.62 %wt. At the same time, some content of accompanying impurities Ca, Mg, Al, Na, Si, Cl, Mn, K, as well as S and P was found in the cinder — in the amount of 0.55-1.52 %wt. and 0.12-0.21 %wt. in accordance. This made it possible to draw a number of important practical conclusions that the obtained product requires the use of aluminothermic refining smelting for further effective use as an alloying chromium-containing additive. At the same time, cinders from leather production waste can be added instead of part of the chromium-containing ore concentrate when smelting ferrochrome. At the same time, the processing and return to production of technogenic waste from leather production ensures an increase in the level of safety and occupational hygiene, a reduction in environmental stress in industrialized areas, a reduction in environmental pollution and an increase in the safety of life.

Influence of Friction on the Formability of Fe-Zn-Coated IF Steels for Car Body Parts

This paper presents the formability results of galvanized Zn-Fe-based interstitial-free (IF) “galvanneal” steel sheets with different degrees of alloying. The Fe content of the Zn-Fe coatings was determined by titration method and the phase composition of the coatings was determined by raster electron microscopy with EDX analyzer. A deterioration of the adhesion of the Fe-Zn coating to the substrate was observed in the pre-alloyed coating. The applied modes of annealing and smooth rolling after the surface galvanization resulted in a change in the surface microgeometry parameters Ra and Pc. The suitability of the surface microgeometry of the used Zn-Fe-coated sheets was assessed using control diagrams and the capability indexes Cpk with respect to the defined specifications. The coefficient of friction was determined by dry friction cup test, and using Anticorit lubricant and microtene film as lubricants. With increasing Fe content in the coating, a slight increase in friction coefficient values was observed—a slight deterioration in formability. The results obtained indicate that for car body surface parts, the Fe content of the Zn-Fe coating should range from 7% to 12%.

The influence of the ZhS6K powder Initial characteristics on the alloy microrelief features after selective laser melting

The analysis of the ZhS6K alloy granules appearance, their surface and internal structure, as well as the chemical composition by volume and structural elements is carried out. The formation control possibility is shown for desired state of interfaces (tracks, crystallization cells, hatch block boundaries, grains, phases, discontinuities - pores and cracks) through the fractional composition, packing density during filling, scanning speed that provide a more solid and qualitative material state of the sample. The initial state of the samples structure was studied. A connection between the structure of crystallization cells boundaries, dispersed par- ticles and the fragments structure has been established. It is shown that all investigated samples have a differ- ent structure at the same power and scanning strategy. The analysis was carried out by optical metallography and scanning (raster) electron microscopy (SEM) methods.

Venous catheters in horses - early ultrasonographic venous abnormalities and evidence of biofilms

Complications associated with indwelling intravenous catheters vary from minor to severe. Changes in tissue architecture and vein structure may be detectable prior to clinical alterations. The aim of the study was to characterize and compare changes in a catheterized vein and surrounding tissue by clinical and ultrasonographic examination. Microbiological infestation of catheter specimens was assessed. In this prospective, observational, clinical study 55 horses with an indwelling intravenous catheter have been included. Subsequent to catheter placement, vein and surrounding tissue were daily examined clinically and by ultrasonographic examination at predetermined localizations. After sterile removal of the catheters, specimens underwent microbiological testing and scanning electron microscopy. Obtained data were analyzed via descriptive statistics. Thickness of the venous wall was compared at predetermined localizations and time points for several parameters with the help of non-parametric tests (level of significance at p < 0.05, post-hoc Bonferroni correction). Overall, in 41.8 % of the horses transient alterations (swelling) of the surrounding tissue occurred during catheterization. Median catheterization was 69.5 hours (19 hour-10 days). With ultrasonography, venous valves and collateral vessels could be detected reliably. Significant alterations in wall thickness during catheterization were associated with various factors (location site [p ≤ 0.001], season [p = 0.006], anesthesia [p ≤ 0.001]).Microbiological analysis revealed a positive result in 23.5 %, 12 of the 51 samples; raster electron microscopy showed presence of bacteria in 25.0 %, 4 of the 16 investigated catheter samples. Local tissue changes at the insertion site of the catheter are commonly associated with catheterization, and are easily detectable with ultrasonography. Despite the easy performance in a clinical setting, the benefit of routine ultrasonographic monitoring of catheterized veins might be questionable with regard to early identification and prediction of catheter-associated venous disease. Bacteria might be detectable morphologically on the catheter but frequently lack a positive result from standard bacterial cultivation.

Determining the influence of technological parameters of the electron-beam surfacing process on quality indicators

This paper reports the technology and equipment designed for manufacturing parts and components with predefined properties by 3D printing methods. Underlying the technology is the use of a beam of high-power electrons to smelt metal powder in a vacuum chamber with the formation of successive layers that repeat the contours of the digital model of the article. The object of research is the process of surfacing articles from the Ti6Al4Vtitanium alloy powder. The purpose is to determine the optimal surfacing modes based on identifying the effect of process parameters on the quality indicators of articles. The result of the study is the analyzed influence of technological parameters on the properties of articles. The optimum energy density of the beam of 44.5 J/mm3has been determined. Based on the research results, 25 experimental samples were printed. Three beam speed modes were used: 270, 540, and 780 mm/s. For each mode, the dynamic focusing current varied from −1.2 to 1.27 A in increments of about 0.3 A. The articles were carefully examined. A method of raster electron microscopy was used to study the morphology of the samples' surfaces in several zones, namely in the central zone and along the contour; the roughness parameters of the surface micro relief, as well as the presence of defects (pores, non-melting, micro irregularities, inclusions), were established. It has been found that the articles are characterized mainly by a homogeneous micro relief of the profile. The structure of surfaces, formed in different zones depending on technological modes, differs in its morphology. Surfacing modes have been established that have the practical application: beam speed, 780 mm/s; power, 675 W; dynamic focus current, from –1.2 to 0 A. This provides for the minimal parameters of the surface micro relief and the absence of defects such as shrinkage pores, non-melting, as well as a minimum number of inclusions.

Obtaining and Study Smart Composites in the B&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;C-SiC-Si-Al-Al&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;O&amp;lt;sub&amp;gt;3&amp;lt;/sub&amp;gt;—Carbon Fiber System

Goal: To obtain SIALON containing composites by reactive sintering method in SiC-B4C-Si-Al-Al2O3 system. Using this method of synthesis, it became possible to obtain composites with different percentages of SIALON. Our task was also to study the phase composition in the SiC-B4C-Si-Al-Al2O3 system. Method: The obtained mass was grounded in an attritor and the consolidated composite was obtained by hot pressing at 1800°C, 40 minutes, delaying at final temperature for 8 min. under 30 MPa pressure. To study the phase composition of the composites, we conducted an X-ray structural analysis on the DRON-3 device, and to study the microstructure, we conducted research on an optical microscope and a raster electron microscope “Nanolab 7” of the company “OPTON”. The values of the electrical parameters of the study composites were calculated on the basis of the obtained “lgp-t” dependence. Result: In SiC-B4C-Si-Al-Al2O3 system we obtained composites with a matrix composed of: β-SIALON, silicon carbide, corundum and nanoparticles of boron nitride. Conclusion: The phase composition of the obtained composite provides high physical-technical and performance properties of these composites. Compression strength—2187 MPA, Bending strength—285 MPa, Thermal expansion coefficient a20-700-3.8 × 10-60 C.

ВЛИЯНИЕ ПАССИВИРУЮЩЕГО ПОКРЫТИЯ НА СТРУКТУРУ АЛЮМИНИЕВОЙ МЕТАЛЛИЗАЦИИ НА КРЕМНИИ

The surface quality of the metallized contact pads on the crystal plays an important role in the production of semiconductor devices. This paper presents experimental studies of the effect of a protective passivation film of silicon oxide on the surface structure of aluminum metallization in the field of forming contact pads. Plasma chemical deposition of passivation layer SiO2 from gas phase (PECVD method) was carried out on prepared samples of silicon with aluminum metallization using a high-frequency power source with a frequency of 13.56 MHz. After that, chemical etching of precipitated silicon oxide was carried out to simulate the process of forming contact areas of semiconductor device crystals. The resistance of the metallization surface to plasma processes was studied by raster electron microscopy. It is shown that as a result of the process cycle, defects of the dislocation type are generated in the applied film Al. The nature of the observed defects has been found to be different. The revealed large square-shaped pits with a size of ~ 1 μm at the places where dislocations come to the surface are of a single nature and appear independently of the processes of applying passivation coatings, which is determined by the orienting action of a single-crystal substrate having some low dislocation density. While the second type of defects, shown by the presence of etching pits measuring ~ 100-300 nm, is characterized by a higher surface density. Moreover, the exclusion of the passivation process with silicon oxide did not lead to the appearance of this type of defects, which determined their nature associated with the ion bombardment of the Al layer during the plasma chemical deposition of silicon oxide from the gas phase. It is also shown that a feature of this type of defects is their disorientation both with respect to the first type of defects and with respect to each other. Detection of the structure of the metallization layers was carried out by X-ray diffraction, the results of which show the polycrystallinity of the formed aluminum metallization. The preferred orientation of the aluminum film corresponds to the substrate Si (111).

Formation of Nitride by Electron-Beam Irradiation of Titanium in Nitrogen Media

This paper demonstrates the possibility of nitriding of titanium by a forevacuum electron source. We present an original design of the experimental setup and the measurements of the tribological properties and elemental composition of the subsurface layer of the titanium experimental sample. Raster electron microscopy analysis of the nitride sample have demonstrated that titanium and nitrogen are found to be the main chemical elements; oxygen and carbon also present, though their total concentration does not exceed 6 wt. %. The thickness of the modified layer after a 75-minute long process of nitriding was about 8 µm. Wear resistance test of have shown that the nitrided sample has a 500 times less loss of the material as compared with the original titanium sample, meaning a times-fold increase of resistance to wear.

CОЗДАНИЕ МЕХАНИЧЕСКИМ ЛЕГИРОВАНИЕМ Ti-Al ПОКРЫТИЙ С ДОБАВКАМИ КОБАЛЬТА И НИКЕЛЯ

The work is dedicated to the formation of TiAl titanium aluminide coatings with cobalt and nickel additives by means of the method of mechanical alloying with the further maturing at high temperature in vacuum. Coatings were applied with the use of the ball mill of the planetary type upon VT1-0 titanium alloy substrate which were placed in the mill cup filled with metal powders. There is studied growth kinetics, a coating thickness is measured. A specific rate of metal powder sedimentation upon a titanium substrate makes from 4.6 to 11 g/(min•m2). Deposited layers have a mean thickness 70-180 mkm. There are studied thoroughly compositions and microstructure of mechanical-alloyed coatings. For that there were used methods of X-ray diffractometry and raster electronic microscopy. It is defined that the inner structure of coatings is heterogeneous. After deposited layer thermal treatment a metal interpenetration takes place first aluminum into particles of titanium, cobalt or nickel. Coatings are composite material the basis of which makes aluminide of RiAl titanium, and as inclusions there are other inter-metallides, titanium, cobalt or nickel and also aluminum oxide. Mean values of micro-hardness of coatings obtained are 1.2 - 3.4 times higher than of titanium substrate. The highest values of micro-hardness (more than 6.5 GΠa) after thermal treatment in vacuum are observed in TiAl-5%Co and TiAl-10%Co coatings. Micro-hardness of VT1-0 titanium alloy after annealing, vice versa, decreases by 1.3 times.