摘要: A study of phase composition, texture and structure of electrolytic Fe-Mo deposits is presented. It was proven that molybdenum changes the parameters increasing the dispersiveness of the plating structure. It is also explored that electrolytic Fe-Mo deposits can be used as strengthening ones.
摘要: An adhesive composition is used as a binder in many composite materials. Crack resistance of an adhesive composition is the most important characteristic determining the bearing capacity of composite materials. To date, a significant number of methodological recommendations and standards have been developed for estimation of adhesive compositions bearing capacity in different types of loading forces exertions which, with certain assumptions, can be used to assess their crack resistance. Known testing procedure for crack resistance of adhesive composition was selected as a basic one. It includes a bending load in the form of loadings acting perpendicular to cantilever beams which is applied to the double-cantilever sample. Therewith a sample response and a corresponding change in length of the resulting crack in the adhesive compound layer are being recorded. This is followed by a determination of the specific energy of crack propagation which provides information about the value of crack resistance.
摘要: It was experimentally found that during the passage of the impact momentum through multi-indentor impact system the distortion of energy transfer in the deformation zone is influenced by such factors as the number of indentures (waveguides), their shape and distance position relative to the impact axis. Thus, the increase in the number of indentures in the impact system, on the one hand, leads to a decrease in the proportion of energy of the impact pulse per an isolated indenter, and on the other hand allows to increase the total value of energy transfer in the deformation zone compared to one-indentor scheme. The distance increase between impact axis and indentors placement regardless of their number and form, leads to a decrease in the proportion of energy transmitted to the deformation zone.
摘要: The purpose of the investigations carried out is the formation of qualitative nanostructured coatings and development of methods for their application on product surfaces. The principle of a staged study of regularities in the formation of vibration mechanical-chemical coatings from “top to bottom” and “bottom-up” formed a basis of a methodological approach to investigation carrying out. Experimental researches were carried out with the use of specially developed working chambers installed upon vibration machines. As an indenter there were used metal balls 2-5 mm in diameter and made of steel of ShH15 type, samples material – steel 45. The assessment of coating characteristics was carried out with the use of optical, raster scanning probe microscopy. It is determined through the result in the investigations of the impact-pulse interaction of a working environment part under conditions of vibration impact that there are grindings and changes in particles dimensions up to 100 nm and lesser in coating material which allows them to penetrate into micro-and nanocavities of basic metal and, in such a way, to form coating with high antifriction properties. The influence of amplitude-frequency properties of vibro-wave activation upon quality and performance attributes of coating surfaces and also process duration is determined.
摘要: Studied the effect of the introduction of vanadium and cobalt into the charge powder fused wire system Fe-C-Si-Mn-Cr-Ni-Mo-V, used in cladding assemblies and equipment parts and mechanisms operating under abrasive and abrasive shock loads. the cored wires samples were manufactured in the laboratory conditions and using appropriate powder materials and as a carbonfluoride contained material were used the dust from gas purification of aluminum production.
摘要: The article studies the structure and properties, regularities of their change with the introduction of various fillers and under the influence of gamma – irradiation (γ-radiation). PCM structure study was performed using electron microscopy with scanning electron microscope BS -350 (TESLA) and with X-ray structural analysis method using X-ray diffractometer DRON-3. Shooting of wide-angle X-ray patters was performed in the range of Bragg angles reflection 2Q=5° - 96°. We selected the following properties to study: tensile strength, static tensile modulus. The findings allowed determining: firstly, we determined that based on electron microscopy the supramolecular structural organization depends on the type and percentage of filler in PTFE matrix. Changes take place from lamellar (pure PTFE) to a defective spherulitic (20% of coke) structure. Secondly, we completed X-ray structural analysis (we determined the degree of crystallinity, crystallite size, with parameters а = b in the hexagonal cell, interlayer distance of amorphous area) showed the nature of supramolecular structure changes according to the nature of the filler and subsequent radiation dose. Thirdly there was conducted connection between changes in mechanical strength (tensile strength, statical module of elasticity) and structural changes; the depth of these changes depends on the original supramolecular structure, type and percentage of the filler and the dose of the absorbed radiation energy. The studies will allow change purposefully the supramolecular structure of polymer composite materials to improve the performance properties.
摘要: The article is dedicated to investigating the problem of increasing the efficiency of modular cutting tools with indexable inserts made of hard tool alloys and to describe the most typical types of their damages. The article justifies the relevance of studying the temperature effect of cutting inserts made of (Ti,W)C–Co group hard tool alloys on internal microstresses of the 2nd kind. It contains the data of X-ray studies of samples of hard (TiC 30% WC 66% Co 4%), (TiC 15% WC 79% Co 6%) and (TiC 5% WC 85% Co 10%) alloys using XRD 7000 Shimadzu Maxima automated diffractometer with an add-on heater at temperatures from 20 to 700°C.
摘要: The paper presents the results of study on artificial strain ageing of tube steel. Temperature fluctuations accelerate ageing processes in steel resulting in changes of its microstructure. Effect of strain ageing on mechanical properties of steel has been assessed during impact strength tests.
摘要: Changes in the structure and the tungsten surface erosion by hydrogen plasma irradiation are studied in the article. It is shown that the change in the surface topography as a result of the development of the non-homogeneous surface etching is observed after surface irradiation. Metallographic analysis showed that the degree of relief is low in comparison with tungsten sample irradiated at T=700°C by tungsten samples irradiation at T=1000°C and 1500°C. However, these samples have small cracks, while the temperature increases the size and number of cracks also increases. It is determined, that the surface roughness varies depending on the irradiation temperature after hydrogen plasma exposure. The greatest increase in the roughness occurs in samples irradiated at T=1500°C, which is associated with the formation of small cracks in the surface layer. It is shown that a degree of surface erosion is increased with increase of the target temperature and the ion energy. Appreciable tungsten erosion due to irradiation of the plasma flow, plasma simulating stationary mode occurs only at relatively high temperatures of the target.