Papers by Keyword: Metal Surface

Abstract: The polymeric adhesives for the installation of basalt elements on a metal base are designed primarily for environments with increased chemical and mechanical stress. They are composed of polymer resins (epoxy, polyurethane) as binders, as well as organic additives and mineral admixtures that mainly fulfill the function of filler. In all sectors of today's construction industry, maximum efficiency in the production of materials is required for sustainability purposes, which, however, must never be at the expense of the quality or the required performance. Due to these requirements, great emphasis is placed on the maximum use of secondary raw materials. Talc is used as the primary filler for polymer adhesives. Sawdust, tire rubber, and fly ash are used as secondary raw materials. The use of these in building supplies can positively affect some physical and mechanical properties of polymeric adhesives. Also, the use of secondary raw materials has the above-mentioned ecological benefit. Basic properties, such as bulk density and adhesion to both metallic and basalt elements, were monitored. The details of the cohesion of the adhesive with the bonded material, as well as the distribution of secondary raw materials in the polymer matrix, were assessed microscopically.

Abstract: The paper reveals the key features of metal products deformation-strength properties obtained by them as a result of plasma-cavitating treatment. A strengthened cold-rolled tape of steel grade 08ps (Russian State Standard (GOST) 1050-88) was chosen as a model object. Samples of the tape were treated by plasma-cavitating method at certain values ​​of technological parameters (power density and time of plasma action). Then they were tested in accordance with Russian State Standard (GOST) 11701-84. It is determined that the strength of the material remains at the level before processing. At the same time, the percent elongation at break increases essentially (up to 36.3% in relation to the initial indices). It is shown that the dependencies of change in plastic properties of the material on processing time at different values of power density are non-linear with critical points of relative change of percent elongation minimum, due to those physical processes that occur during the treatment period. The location of these critical points depends on both the power density and the time of plasma-cavitating treatment.

Abstract: The paper presents the principal advantages of plasma-electrolytic coating method that characterize it as a highly promising technology. It is shown that these advantages are provided by the integrated nature of the effect, representing a combination of the main types of impacts on a surface: electrical, thermal, mechanical and chemical. This combination distinguishes the method of plasma-electrolytic treatment from many other widespread in up-to-date technology combinations composed generally of two types of impacts. It is suggested that the process of plasma-electrolytic coating is carried out by the mechanism of metal pressure welding that is confirmed by the results of tests for determining quality ratings of coatings. It is shown the thermodynamic and kinetic unity of these processes that allows plasma-electrolytic coating to be put in class of metal pressure welding processes and to consider the processes of coating by plasma-electrolytic method and pressure welding from a common methodological framework. The paper presents the results of the structure and composition studies of zinc plasma-electrolytic coatings on a strip for armoring cables of group A (GOST 3559-75). The researches were carried out using scanning electron microscopy, microroentgenspectral analysis and differential scanning calorimetry.

Abstract: We investigated positron states at Li-adsorbed Al(100) surfaces using \textit{ab-initio} two-component density functional theory. The results thus obtained by using semi-local electron-positron (e-p) correlation functionals with the generalized gradient approximation well reproduce the experimental results, showing that reliable e-p correlation functionals are needed to properly describe the various properties of positron surface state.

Abstract: In the article we selected polyethylene glycol(400), triethanolamine, silane coupling agent, chrome alum, glycerin as the main raw material, and systematic studied the chemical adsorption film technology on metal surface by using one step. Through the preliminary experiments, we optimized the optimum technological conditions. The trial results showed that the process and procedures to deal with were simply, and the tank liquor was stable. The chemical adsorption film accumulation was closely, and it had stable structure. It had a good anti-base metal corrosion, and significantly enhanced the adhesion of metal coatings.

Abstract: A strong pulse electromagnetic field was employed to treat the surface layer of several metal materials. The results showed that the treatment of the strong pulse electromagnetic field could modify the microstructure of the region around the crack on the 45^# steel surface. It could also make the recovery process occur in the scratch on the brass surface, and make the surface layer of the Wood’s alloy melt in a very shot time. These results indicated that the strong electromagnetic pulse could be developed as an effective non-contact method for the metal surface processing.