Seznam abstraktů 2019: POSTEROVÁ SEKCE D

The electropolymerization of EDOT/PyBA/BRIJ by cyclic voltammetry on stainless steel and glassy carbon was studied in aqueous solution. The protective properties of the resulting coatings on stainless steel were investigated in the aggressive medium of 0.25 mol dm-3 K2SO4 + 0.5 mol dm-3 KCl with pH = 2. Diagnostic experiments included measurements of potentiodynamic polarization.

The influence of the nature of organic additives on the rate of low-temperature chemical deposition of nickel is studied. The class of organic compounds allowing to obtain adhesion coating of chemical nickel was revealed. The temperature ranges of the process are determined. The regularities of temperature influence on the rate of chemical deposition and the quality of the deposited coating are obtained. Mechanical tests were carried out on the samples obtained by this method.

In this paper presented the main problem of wear of sapphire wire guides on EDM machines significantly affects the quality and accuracy of the machined surfaces. Even small geometrical deviations lead to errors in the technological process. This is particularly important in the production of hydraulic motors, where deviations of several dozen micrometres lead to a decrease in the efficiency of the engines. The reduction in torque is caused to leaks due to incorrect technological process and shape errors. Therefore, from this point of view, this type of machining is extremely important from the point of view of the quality of hydraulic motors produced. I this work showed the results of the measurement sapphire wire guide especially the hole in which there is cut wire by means of multi-sensor measuring system to be used in the industrial measuring, inspection and quality control. In simulation research using FEM, determined the distribution and values of stresses and strains in surface layer. The depth of location of stresses in numerical simulation allowed to correlation with metallographic examinations of the wear surface. Depending on the technological parameters (wire speed, wire tension or water pressure), it could be forecast the intensity of wear the sapphire wire guide. This is important to determination intensity of wear and when we should replace guide before we obtain no acceptable roughness surface on industry detail.

This study developed how the changing of distance between electrodes in the anodizing process affects the surface morphology and mechanical properties of oxide coatings. Oxide coatings were prepared on aluminum alloy samples. The samples surfaces were subjected to hard anodizing process in a multicomponent electrolyte based on sulphuric acid with an addition of organic acids. Anodizing was carried out with a constant electric charge density and constant electrolyte temperature. The distances between the electrodes for subsequent samples increased. The pictures of the oxide coatings surfaces were collected by scanning microscope. The ImageJ software was used to analyze the nanomorphology of the coatings. The thickness and microhardness of the oxide coatings was determined by contact and Vickers method respectively. The geometrical structure of the surfaces of oxide coatings was determined by contact profilograph. Based on the conducted tests, it can be concluded that changing of parameters during the anodizing process influence on the surface morphology and microhardness of the oxide layers. The tests have shown that with the changing of the distance between the electrodes, the nanoporosity has changed.

Geo-components are manufactured from steel, galvanized steel and polymers commonly take the form of reinforcing meshes, straps or strips for high quality erosion and sediment control systems. Prediction of durability of zinc/zinc alloyed coatings can be done on the basis of knowledge of their thickness and zinc/zinc alloyed corrosion rate in soil. Required durability of these systems varies from 20 to 120 years depending on soil corrosivity. The paper gives some data for short exposure of zinc/zinc alloyed coatings in soil. The performed tests show that the corrosion attack of zinc coating in soil is very non uniform and locally may be totally corroded after few years. In such case the service-life of geosystems may be significantly lower that required according to standard and producers specification. Performed tests show the additional protection by PVC coating may be damaged due to installation of geosystems and corrosion of wires may started immediately.

Antibalistic ceramics has many material and shape variations, depending on the specification of its use. The aim of our research was the hardest materials with the lowest density, designed for light armor. For example, SiC, B4C, TiC, and TiB2 compounds meet this criterion, but they are highly brittle after sintering. Their utility value, especially the reduction of cracking or brittle fracture, is multiplied by incorporation into the cermet structure. However, in the preparation of titanium matrix cermets, other binary compounds are formed which alter the stoichiometry of the input compounds and affect the final mechanical properties of the resulting composite. Their formation by the diffusion mechanism and their amount is influenced by the temperature and the time of contact of the matrix and the filler. The PTA hardfacing method made it possible to reduce the time of existence of cermet components in the liquid state and reduce the content of undesirable components. The welds of Ti-SiC and Ti-B4C cermets on the carbon foil mats or titanium alloys were made by the hardfacing plasma automate PPC250 R6. The cermet, formed from a mixture of elemental Ti and hexagonal SiC in various stoichiometric ratios, was deposited by welding technique. Despite the relatively short heating time, tetrahedral TiSi2 was detected in the product. Similarly, boridated substrates with a Ti-B4C cermet coating were prepared and the optimum stoichiometric composition was sought to achieve the maximum TiB2 content, characterized by a high hardness of HV 27 GPa. The prepared samples were subjected to the antiballistic resistance test against the 38-special caliber projectiles.

This paper deals with welding on high-carbon steel that is used for the production of tram and railway tracks. The high-quality and efficient maintenance of the track superstructure, especially the refurbishing of worn rails, is an integral part of the operation of rail transport. The rails are subjected to wear and tear and their overall replacement is wasteful and time-consuming, too. Therefore, refurbishing technologies are used that enable us to extend the lifetime of parts applied in technical practice. During the actual operation, the rails are worn out considerably in exposed places, such as the tramway curves in city transport or railway turnouts and frogs of both tram and railway lines. When welding the rails, the aim is to achieve better wear resistance and, at the same time, to comply with all conditions and regulations for rail transport. This article presents new findings concerning the application of an interlayer with additional material that is different from the additional weld deposit material itself. Furthermore, it deals with the study of transition areas and their influence on the structure in the areas of weld metal, the interlayer, the heat affected zone and base material and mapping the influence on hardness and microhardness. Welding on worn rails using suitable technology can guarantee the unlimited repeatability of welding on further worn weld deposits. The paper evaluates the weld deposits with various additional materials under different welding conditions with the aim of improving the quality of rail refurbishing.

The effect of the ratio of the pigment volume concentration (PVC) to the critical pigment concentration (CPVC) belongs to well-known formulation design practices for optimized performance of pigmented organic coatings. The influence of this ratio in Zn an Al pigmented epoxy coatings on delamination kinetics of underlying steel has been investigated by electrochemical noise analysis (ENA) during 168 hrs immersion tests in 0.05 M NaCl. Two different Zn and Al pigmented epoxy coatings were prepared with different PVC/CPVC values but with the same vol. % Zn:Al ratio as well as with the same binder and hardener types applied. ENA was used to provide information about possible effect of PVC/CPVC values on delaminated corroding area time development in tested coating/steel systems. It has been concluded that in these systems it is recommended the use of certain low PVC/CVPC value in order to obtain high resistance to possible coating delamination from the metallic surface.

The martensitic stainless steel AISI 410 was subjected to plasma nitriding at an increased temperature of 550 °C, 24 h in 3H2:1N2 (l/h) nitriding gas ratio and compared to untreated one. The microstructure and microhardness of the untreated and nitrided stainless steel were evaluated. The corrosion properties of the untreated and plasma nitrided steel samples were evaluated using the anodic potentiodynamic polarization tests in neutral 2.5% NaCl deaerated solution. The phase analysis of nitrided steel sample was compared to untreated one. The results showed that plasma nitriding process on the X12Cr13 Steel (AISI 410) stainless steel produced a nitride layer consisting of compound layer and a nitrogen rich diffusion layer with iron carbides Fe3C, iron nitrides Fe4N, chromium nitrides Cr4N4 and chromium iron carbide Cr15Fe7C6. Plasma nitriding process significantly increased the surface hardness of the martensitic stainless steel but also decreased the corrosion resistance. The pitting and type of corrosion were evaluated, and the pitting coefficient was calculated. During electrochemical corrosion tests, the nitrided AISI 410 stainless steel showed lower corrosion potentials (more negative), higher current densities (nearly forty times higher) and nearly forty times increased corrosion rates compared to untreated X12Cr13 stainless steel.

The presented paper contains the results of research on fractal analysis. The fractal analysis was carried out on X39Cr13 steel subjected to heat, surface and thermo-chemical treatments. The research was carried out according to various variants: hardening + tempering (H/T), hardening + tempering + surface treatment (H/T/N, hardening + tempering + surface treatment + sterilization (H/T/N/S), hardening + tempering + sterilization + corrosion resistance test (H/T/S/C, hardening + tempering + surface treatment + sterilization + corrosion resistance test (H/T/N/S/C). Spatial characteristics of the surface texture of steel samples were derived from SEM images.

Diamond-like-carbon coatings (DLC) have exceptional chemical, protective and tribological properties. They are increasingly used in industry. DLC coatings are characterized by high hardness, resistance to chemical agents and low coefficient of friction and it is a reason to check of its use in tribological pair cooperation in automotive means of transport. The main goal of the article is to determined tribological parameters of DLC layers and to check the possibility of its using for the regeneration of injector elements for the self-ignition engine, which is the injector needle in Common Rail system. This component is responsible for proper operation of the injector (opening and closing) and is made as a precision pair with a injector socket. The injector needle cooperates with the socket in a reciprocating manner, which leads to the wear of these elements and appearance of seizures. Fuel quality is also an important issue. Currently, DLC layers are used in industry, but their application in the processes of regeneration of precision parts in means of automotive transport is rather marginal. The article presents the results of tribological studies of DLC layers used as regeneration layers for self-ignition engines injectors in Common Rail system. On the basis of the obtained test results, it can be concluded that the use of DLC coating on the surface of selected parts of cooperating injectors in the Common Rail system will allow for longer life.

Copper and nickel-based solders with embedded particles of various sizes of tungsten carbide are widely used in industry. These particles are characterized by high hardness and abrasion resistance, erosion resistance, etc. They can be applied both during renovation and in the manufacturing of new parts for decrusters, screw conveyors and other stressed parts. Each of these parts requires a different surface character, and therefore, a different size of the tungsten carbide particles in the tough solder matrix. Machine components with a deposition soldered surface can be classified into the group of composite materials to replace standard parts from quality steels. The tested soldering materials based on Ni, Cu were applied to the surface using solder brazing technology on the substrate steel S235JR. The diameter of tungsten carbide particles used in these matrices ranges from 38 µm up to 6.0 mm.
This research is focused on assessing the microstructure of selected areas, microhardness measurement and a microstructure analysis using a scanning electron microscope. Using a spot chemical analysis, the movement of partial chemical elements between the base material, solder and carbide particles was investigated.

This article deals with the reinforcement of epoxy resin with different carbon fillers in various concentrations. The properties observed in this paper were electric conductivity, hardness and chemical and electrochemical plating. The data obtained from the measurements of electric conductivity and hardness were subsequently examined and discussed.

Friction stir surfacing (FSS) is a kind of materials welding in the solid state. This process of cladding material to the surface allows to obtain coatings with special properties, repair products, etc. The geometry and properties of the resulting coating largely depend on the temperature field formed in the body of the consumable tool. In this paper, using the example of aluminum alloy Al-Mg5 cladding on a steel substrate C20, a mathematical model for calculating the temperature field was developed.
In these paper, the CFD method was used to study the temperature field and material flow. A 3D steady state viscoplastic model has been developed. Volume of Fluid (VOF) approach is used. The temperature field and material flow in the tool are studied. In addition, the numerical model can be used to optimize the axial force parameter of FSS process.

The issue of anti-frost surface treatment is a current research topic, especially in the transport and energy industries. Ice and its formation, adhesion and accumulation can cause serious problems on the surface of wind turbines, solar panels, power lines, roadways, in aircraft industry as in everyday life. These aspects can reduce energy production efficiency, increase energy consumption, cause mechanical or electrical failure, and increase security risks. This article deals with the wettability of surface treatment and its influence on the formation of icing on metal surfaces. In this study, new method for fabricating anti-icing coating was employed. The metal samples were first surface treated and afterwards the anti-icing coating for titanium alloy samples was applied and coating properties were examined. Various surface treatment steps were tested for the coating anti-icing properties. The formation of icing was experimentally tested on modified surface of metal substrates. Wetting properties of the titanium surface was evaluated by contact (wetting) angle measurements. The surface structure of the metal samples was examined by SEM (Scanning electron microscopy). Testing of anti-icing properties of the surface treatment took place indoors. Physical and mechanical properties of the samples were evaluated before and also after the testing at low temperature.

The main purpose of the work was to modify the surface layer of copper using FSP technology (Friction Stir Processing). The surface treatment was performed using a tool equipped with a threaded pin. Changes in the microstructure of the material were evaluated by light microscopy and scanning electron microscopy. Comparative measurement of the hardness of the starting and treated material was also carried out. It was found that the friction modification leads to strong refinement of the copper microstructure and the formation of zones with different sizes and morphology of the grains. In the stirring zone, the presence of very fine, mostly equiaxed grains, measuring from 3 μm to 32 μm, depending on the location in the zone, were revealed. In the narrow thermomechanically affected zone that intermeshed with the heat affected zone, non-equiaxed grains of an elongated shape prevailed. The observed changes in the copper microstructure were accompanied by a significant increase in hardness, the value of which corresponded to the degree of microstructure fragmentation. The results of the research prove that using FSP technology to modify the surface layer of copper is an effective and promising solution with a high application potential, allowing controlled shaping of the material microstructure and an alternative solution to other methods and technologies used in surface engineering.

This paper deals with an assessment of the corrosion resistance of copper-basalt composite cladded by laser. The filler powder for laser overlaying was a mixture of high-purity copper powder Oerlikon METCO 55 consisting of 45-90 µm particles and a basalt powder comprising particles 50-250 µm in size. Under this experimental programme, three series of specimens were prepared (5 wt. % basalt; 10 wt. % basalt; and 15 wt. % basalt). The substrate was C45 steel 20 mm in thickness. The corrosion resistance of the laser clads was assessed by potentiodynamic corrosion testing using the linear polarization method. The electrolyte was an synthetic prepared mine water. Metallographic evaluation of the laser clads was carried out using optical microscopy (OM) and scanning electron microscopy (SEM). Based on the outcomes of this study, a summary was developed of the application potential of the laser-deposited composite copper-basalt overlay for surface treatment of storage containers for underground spent nuclear fuel repositories located in the Czech Republic.

This paper presents the possibility of modifying the microstructure of anodic hard coatings on aluminium alloys by applying a pulsed method in the process of their electrochemical deposition. Anodic hard coatings were formed on an aluminium alloy intended for plastic working. The electrolytic process was conducted using the pulsed method with a rectangular current waveform in time, applying variable frequencies, current densities and duty cycles of the waveform. Examination of the microstructure of the anodic hard coatings was carried out by image analysis of the images obtained by means of SEM from fractures of the coatings. The obtained results indicate that the application of the pulse anodizing method results in the occurrence of local changes in the microstructure of the anodic hard coatings.

Anodic oxidation of aluminum alloy in a ternary solution of SAS (sulfuric, adipic and oxalic acids) was carried out in order to obtain the aluminum oxide layer (Al2O3) and Al2O3 with inorganic fullerene-like tungsten disulfide (IF-WS2) named in article as Al2O3/IF-WS2. The micro-hardness, thickness, geometric structure of the surface (SGP) and the microstructures of Al2O3 and Al2O3/IF-WS2 were investigated. The influence of electrolysis time, temperature and type of electrolyte on the micro-hardness of coatings was studied using the Taguchi statistical method. A L2 orthogonal array with the three main factors of control at two levels each was studied. Signal-to-noise ratio showed that the great influence of temperature on micro-hardness. The optimized electrolysis conditions were defined.

The article presents an analysis of the consumption of low-carbon steel and DLC coating working in a sliding combination with rotational motion and in various operating conditions. The influence of selected operational factors, i.e. the speed and load on wear and the coefficient of friction in sliding combination, as well as their graphical interpretation of test results based on the results obtained from experimental and metallographic investigations are shown. Tests carried out at the tribological stand T01M operating in the stem-disc system were preliminary tests. Initial tests allowed to determine the influence of the determined operating parameters on selected tribological properties. Low-carbon steel, designed for thermo-chemical treatment and DLC coating, was used for the tests. Metallographic examinations allowed to determine the dominant mechanism of wear, depending on external factors.

The generally applied requirements on lowering of emission production in the field of power industry have led, among others, into the application of low-emission combustion process of coal fired power plants. Besides the emissions reduction, this process has led to an increase of boilers parts corrosion degradation due to the reducing atmosphere in low-emission boilers, responsible for sulphide corrosion and molten salt attack. In such environment, the protection of the exposed surfaces gains importance. Among others, the thermal spraying technology can offer a suitable way of surface corrosion protection. In the present work, the high temperature corrosion behaviour of CoCrAlYTaCSi and Cr3C2-25%NiCr High Pressure/High Velocity Oxygen Fuel (HP/HVOF) sprayed coatings is evaluated and compared to the behaviour of bare structural steel (SPT360) substrate. The specimens were exposed to a molten salt environment, i. e., 12% Na2SO4 + 82% Fe2(SO4)3 at 690 °C under cyclic condition, simulating the working environment in low-emission boilers of coal-fired power plants. The thermogravimetric method was used to establish the kinetics of corrosion. X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) techniques were used to analyse the corrosion products and determine the corrosion mechanism. The thermogravimetric measurement shows high oxidation rate of SPT360 steel. Cr3C2 25%NiCr coating provides slightly better performance compared to CoCrAlYTaCSi coating. Based on the obtained results, both coatings were found to have higher corrosion resistance than the SPT360 steel substrate, offering a sufficient surface protection in a given environment.

The construction material during corrosion processes loses its properties, it causes deterioration of functions, loses its usefulness, applicability. One of the important aggressive environments in the building as well as agricultural, chemical and energetic industry is nitrogen, from which nitric acid may be formed. Due to high economic and also a good resistance to mechanical characteristics, good weldability and corrosion the 1.4162 steel is commonly used in industry as chemical, pulp cellulose industry, oil and gas industry, building industry. The aim of the research was to determine the corrosive wear of 1.4162 steel, corrosion resistance with ferritic-austenitic microstructure using the Huey test. The tested steel contains 0.03 % C, 21.2 % Cr, 1.42 % Ni and 5.0 % Mn. The samples were weighed before start of the corrosion processes and after them. Samples were kept in nitric acid 65 % at temperature 332 K. The holding times of the samples in nitric acid were 48, 96, 144, 192, 240, 288, 336, 384 hours. The percentage of mass losses was determined by the weight method. Each sample was examined metallographically using an optical microscope and the surface roughness test using a profilometer. The test results were analyzed in order to determine the corrosion rate of steel in mm/year and g/m2 as well as percentage mass loss and determine the corrosion resistance in this environment. After corrosion of the steel, the roughness and mass loss has increased. Then it was confirmed that as the holding time in boiling nitric acid increases, corrosive wear increases.

Stainless steels are considered to be a perspective candidate as a bipolar plate material for the polymer electrolyte membrane fuel cells. The main reasons for using this material are properties such as low cost, high strength, electrical and heat conductivity and reasonable corrosion resistance. The aim of this study was to test several stainless steels in simulated environment (acidic and humid environment at 80 °C) for application as bipolar plates. The experiments were carried out in an electrolyte of pH 3 with addition of 0.1 ppm HF. Potentiodynamic and potentiostatic polarization according to United States Deparments of Energy was used for electrochemical testing. Open circuit potential, polarization resistance, corrosion current density and corrosion rate from the Tafel extrapolation were determined on the basis of measured data. The suitability of using different types of stainless steels as a bipolar plate material for fuel cell has been evaluated.

The durability of materials working in aggressive environments is mostly important in the design of structures and devices. Corrosion destruction is one of the main causes of material losses, reduced efficiency and safety of their use. Corrosion cannot be completely eliminated but it can be significantly reduced by using different methods of protection. Proper design of structures working in aggressive environments, the use of protective coatings or environmental modification significantly reduces the rate of corrosion. Corrosion inhibitors are also used to protect the structural elements. An addition of a small amount of a chemical compound or a mixture of corrosion inhibitor compounds results in a significant reduction of the corrosion rate. To select a proper corrosion inhibitor and proper concentration for a specific corrosion system, laboratory tests are carried out. The article presents the results of research on determining the effect of inhibitor - NaNO2 sodium nitrite - on the dissolution kinetics of model constructional steel in water environment and in an aqueous sodium chloride solution. The influence of inhibitor concentration in the range of 0.5-2.5 % on the corrosion rate of steel in a 5% solution of sodium chloride was estimated by assessing unit changes in mass and corrosion rates. The effectiveness of inhibitors was determined using the protection factor ν and the inhibitor efficiency Ef.

Modern applications of pneumatic and hydraulic systems in extreme subsea production increased emphasis on long life and minimum maintenance cycles. For this reason, are constantly developed new sealing elements. These sealing elements require very low surface roughness at the contact surfaces. High geometrical and dimensional accuracy is not required because the inaccuracies are compensated by sealing elements. The aim of this paper is to propose a production technology that can achieve the surface roughness Ra = (0.1 ÷ 0,4) µm and geometric accuracy H11. Machined material is chrome-nickel austenitic stabilized steel F304L according to EN 10088-3 marked 1.4307. This article includes applications of ball diamond finishing machining to turning surface. Appropriate technological conditions have been established. These conditions correspond to the specified surface roughness criterion.

The article deals with porosity of compound layers after gas and plasma nitriding. Experiments are focused on using of gas and plasma nitriding processes for surface treatment. Diffusion technologies were applied to steels C 35 (sample A1) and steel 41Cr4 (sample A2), which were subsequently evaluated by electron microscopy, GDOES, XRD and microhardness methods. Main task was to compare the surface hardness connected with chemical composition of steels and the porosity after plasma and gas nitriding and finally prepare the documentation of pores from surface and from cross sectional structure. Plasma and gas processes were applied for increasing of surface hardness of material in depth and improve mechanical and tribological properties. Mechanical and tribological properties of tested material were significantly increased.

The paper presents investigations of the wettability of Al2O3 layers produced by the direct-current method and the reference to its geometrical structure and tribological properties. The layers were made on the aluminum alloy EN AW-5251 using direct-current anodizing at varying production parameters (electrolyte temperature, current density, process time). The aluminum plates before the anodizing process were etched in 5 % potassium hydroxide, then whitened in 10 % nitric acid (V). As the electrolyte, an aqueous solution of 18 % sulfuric acid, phthalic acid and oxalic acid was used. Wettability of the surface was determined by the embedded drop method (measurement of the contact angle). Free surface energy was calculated using the van Oss-Chaunhury-Good method. Measurements of the geometric structure of the surface were made by systematic scanning, determining the basic stereometric parameters from the amplitude group before and after the tribological test. Tribological tests were carried out using a tribological tester T-17 for reciprocating motion on a road with a length of 15 km, under conditions of technically dry friction. A constant slip speed of 0.2 m/s was used, a load of 0.5 MPa was used. The tests were carried out at a constant temperature of 298 K and 60 % relative humidity, T7W polymer was used as the tribo partner. Using the scanning microscope (SEM) images of the surface morphology of Al2O3 layers were made at the magnification of 5,000x allowing observation of pores.

This paper presents the influence of laser texturing on the tribological properties of sintered tool materials not coated and coated in the process of chemical deposition from the gas phase. Sintered carbide substrate, sialon ceramics substrate and the Al2O3+TiN coating deposited on sialon ceramic substrate were subjected to laser treatment. Neodymium laser Nd: YVO4 was used for laser texturing. The work presents abrasion resistance tests using the "pin on disc" method. The examinations were carried out using a scanning electron microscope (SEM), surface morphology - using atomic force microscope (AFM), confocal microscope and optical profilometer. The chemical composition in micro-areas was also examined by the use of the EDS X-ray energy spectrometer, roughness and abrasion profiles were measured. Subjecting laser treatment, the surface of tool materials, results in changing the micro and nano structure. In the micro scale, so-called lubrication reservoirs, while in the nano scale, so-called nanoripples commonly referred to as LIPSS (Laser Induced Periodical Surface Structures) are created. The value of the friction coefficient ranged from 0.7 for laser-free non-textured surfaces to 0.4 for laser-textured surfaces. As a result of the tests carried out, it was found that the creation of a textured surface layer in micro and nano scale, resulted in a significant increase of tool materials wear resistance.

The article describes the technology and application of anti-graffiti coating systems for rolling stock, i.e. coatings resistant to devastation by graffiti-vandals and easy to be renovated later. Paint systems for rolling stock must fulfill mechanical and qualitative properties to longer maintenance protective and decorative properties on the vehicle. Graffiti spray paints should be treated as dangerous substances for coatings because they contain various solvents and other substances that might soften or migrate into protective coating and cause delamination of the coating system and finally lead to shortening durability of the coating surface. Surface free energy is of interest in the field of coating technologies and cleaning procedures, because it is a factor which affects such surface properties and interfacial interactions as adhesion, adsorption and wetting. The contact angle of a liquid on a solid surface is a measure of a free surface energy so the study of wettability and free surface energy is of great practical interest in industrial processes, especially for paints with special properties like anti-graffiti for rolling stock industry. This paper presents results of the investigation on the free surface energy for the anti-graffiti BO100-AGR coating developed in laboratory of Barwa Company. The system consists of high solid corrosion protection primer, putty, filler, basecoat and anti-graffiti clearcoat. The research was based on anticorrosion coatings system with transparent layer with reduced adhesion of each subsequent types of contamination.

The article evaluates the effect of technological parameters of machining on surface roughness, dimensional and shape accuracy in the process of milling Al2O3 ceramics in hardened state. The unique properties of ceramic materials cause more and more interest in them in various branches of industry. Ceramics in the hardened state can be processed using unconventional methods and conventional methods while maintaining the appropriate technological parameters. Ceramics cutting tests were carried out in a hardened state (face and shape milling) on a CNC milling machine using PCD tools. Geometric surface structure study and measurements of geometric dimensions were made.

In recent years, black nickel-based functional coatings are increasingly being used as a worthy alternative to chromium coatings on steel, since such coatings provide not only an aesthetic appearance, but also effective corrosion protection. The known technologies of applying black nickel coatings do not allow obtaining coatings with the required corrosion and wearing resistance. In addition, these technologies involve the mandatory pre-deposition of copper or nickel underlayer. The aim of the present work is the improvement of the technological process of applying black nickel coatings. Plates of cold-rolled steel were used as samples. A stepwise method of the cathode current density change for deposition of black nickel-containing coatings is proposed. Electrodeposition was carried out from a solution of the following composition, g / l: NiSO4 • 7H2O - 100; (NH4)2SO4 - 15; ZnSO4 • 7H2O - 40; NH4CNS - 15; H3BO3 - 25.

The paper presents research determining the effect of surface preparation on the quality of varnish coatings obtained by electrophorus. The tests were carried out on steel parts used for the construction of trailers and bodies for trucks. The quality of the paint coatings obtained was determined in the corrosion resistance tests carried out using the Ascott CC1000 salt cell. The research allowed to determine the durability of the electrophoresis coating depending on the method of preparation of the surface on which they were applied. In order to supplement the tests, the thickness of the varnish coating was measured. The measurements were made by magnetic induction. In addition, roughness measurements were made to determine the effect of surface preparation on the corrosion resistance of the tested coatings. The tests were carried out before applying the coating and for the obtained varnish coat. On the basis of the presented tests, the relationship between the surface preparation method and the corrosion resistance of the tested parts was determined.

The article presents an innovative method of metallization of ceramics based on detonation spraying process. New approach consists on exposition of influence mechanical deliver of energy for joining process. In the D-Gun spraying process the energy necessary for deposition the metallic coating onto ceramic substrate is delivered mainly in mechanical way. In the described case, the titanium particles, shot from the spraying gun barrel, impinge onto AlN ceramic surface, and their kinetic energy is transformed into heat delivered directly to the zone coating/substrate joint being formed. The powder being sprayed is also heated to a high temperature, however, the high kinetic energy of the particles in the spraying stream is dominant for the distinguishing properties of the coating.

One of the methods of protection of metal surfaces from an aggressive environment is the formation of continuous coating on their surfaces with water-repelling properties and a self-cleaning ability, which give the material superhydrophobic properties and also protect them from contamination. A solution for hydrophobization of aluminum alloy 5556 in a solution containing dimethyl sulfoxide and water in a ration of 7:1 and also stearic acid in the amount of 0.01 mol/L was developed. It was determined that the newly-formed coating in this solution is characterized by a contact angle of θс = 151°. The protective ability of coatings determined by the drop method as the time until the appearance of corrosion product under the drop of Akimov solution amounts to 125 s. Corrosion tests of AA 5556 speciments with hydrophobized surface were conducted (ASTM B117) in a salt fog chamber in the developed solution. The tests have shown that the developed coating withstands 140 h in salt fog conditions (5 % NaCl) until the appearance of corrosion hotbeds on the base, while the unprocessed specimen of aluminium alloy started corroding after 24 h.

Gas nitriding (GN) is one of the oldest and still widely applied surface treatment method improving wear resistance of materials. This process causes a formation of a thick zone, consisting of hard surface layer of nitrides and of a subsurface diffusive zone. GN has been especially successfully employed for titanium alloys, known to suffer from fast wear. It applies also for Ti6Al4V, which is frequently used for implants and alike. However, the literature data suggest, that the carcinogenic properties of vanadium could have a negative effect on human health. The Ti6Al7Nb alloy could make a good replacement due to the non-toxic properties of niobium. Therefore, the present work was focused on the determination of the effect of processing temperature on the microstructure of gas nitrided Ti6Al7Nb alloy.
The optical microscopy (OM) observations of Ti6Al7Nb alloy revealed, that only nitriding processes performed above ~700oC causes evident coarsening of microstructure of base material. Transmission electron microscopy (TEM) observations of the near surface areas showed, that the GN of this alloy causes formation of zone consisting of up to three layers. The surface one is formed by d-TiN phase. Treatment at temperatures up to ~700°C promotes formation of thin and dense layers of nanocrystallites, while processing above that temperature helps to obtain thicker but porous ones. The second layer was built of highly textured grains filled with sets of parallel heavily dislocated platelets of a"-Ti martensite, which could have formed from b-Ti(N) phase on post processing cooling. The bowing out of the boundaries at the bottom interface of this layer denotes the growth direction of b-Ti(N) taking place during nitriding. This process pushes down aluminium and niobium promoting nucleation of Ti3Al phase. The latter consist of relatively large crystallites , which are however separated by matrix a-Ti(Al, Nb) grains.
ACKNOWLEDGEMENTS: Investigations were co-financed by the European Union from the European Social Fund (Project No. WND-POWR.03.02.00-00-I043/16).

This paper shows influence of Laser Shock Peening (LSP) on Residual stress (RS) and Fatigue life of stainless steels. LSP is an innovative surface treatment technique for strengthening metallic materials. The principle of LSP is based on conversion of laser energy into a shock wave that results in material plastic deformation and redistribution of RS. The aim of the RS redistribution is to move the compressive RS to maximally stressed area in component. Suitable RS redistribution in component, can lead to increase of component fatigue life. The paper is focused on the RS change and fatigue life after LSP treatment. The tested material was austenitic stainless steel which is used in nuclear industry. The depth profile of RS was measured by X-ray diffraction (XRD) and fatigue life was examined through the three-point bend fatigue test.

Material coating is a technology that is used in a variety of materials, and thanks to this adjustment, we improve the surface properties. It increases corrosion resistance, wears resistance, improves a functional quality and changes or improves aesthetic design. Increased demands are placed not only on productivity but also on the quality of finished products. The paper deals with galvanic plating. The work experimentally evaluates the occurrence of defects when is comparing the technology of mass and suspension plating. The research focused on the progress and evaluation of the results obtained in the experiment. There were performed the control measurements of coating thicknesses, was controlled the correct ratio of elements of the alloy used for electroplating and visual inspection of defects in products. The results of the work should contribute to the comparison of the technology of drum and hinge method of galvanic coating with ZnNi alloy. The aim of the thesis is to compare possible defects and propose measures for their removal. The correct coating thickness does not only increase the life of the product, but also has a significant impact on the quality of the final parts.

The impact of application of Laser Shock Peening (LSP) to surface microstructure of silicon steel (Fe-Si 6wt %) was studied. LSP by high intensity laser nanosecond pulses generates high-pressure shocks at sample surface. Sample surfaces after LSP were characterized by scanning electron microscopy (SEM), X-ray diffraction, and Mössbauer spectroscopy. The surface layer was partly remelted and oxidized. Changes in surface structure and phase composition are described in details.

This work is devoted to experimental research of the influence of technological parameters of plasma-electrolytic modification on the structural-phase condition, also changes in the mechanical and tribological properties of the surface layers of structural steel 0.3Cr-1Mn-1Si-Fe after plasma-electrolytic processing. Metallographic analysis methods using «NEOPHOT-21» and «AXIOPHOT-2» optical microscopes, X-ray diffraction analysis on X'PertPRO and XRD-6000 diffractometers in monochromatic CuKα radiation, as well as elemental analysis on scanning electron microscopes FEIXL-30-FEG and JSM6390-LV, mechanical testing for microhardness on the installation PMT-1M, methods for measuring wear resistance according to the “ball-disk” scheme and corrosion resistance obtained the following results: microstructure of steel 0.3Cr-1Mn-1Si-Fe after nitriding in electrolyte plasma according to mode 1 consist from α-phase and iron nitride (FeN); and mode 2: at a temperature of 700-750 °C with a treatment time of 3-7 minutes, a layer consisting of α-Fe, oxides (Fe2O, FeO) and iron FeN nitride and ε- is formed in the electrolyte, which is characterized by ammonium chloride (NH4Cl) content phases (solid solution based on iron nitride Fe3N) with a thickness of 30 μm, which is highly resistant to corrosion. It was determined that after plasma electrolytic nitriding at a temperature of 850 °С for 7 minutes, the wear rate as compared to the initial state of the 0.3Сr-1Mn-1Si-Fe steel samples decreased 4.3 times.

Alloy galvanizing with nickel content is a high corrosion and heat resistant coating that meets the high demands of the automotive industry. The plating is galvanic, and the deposited alloy coating is protected by final treatments (passivation and sealing). These treatments cause non-conductivity of the surface coating of the material. The scanning electron microscope (SEM) equipped with the EDX microanalyzer can determine both the coating thickness and its chemical composition, as well as the composition of the base material and another structural component, for example, inclusions. Its drawback is the missing or inaccurate detection of carbon and other light elements. Glow Discharge Optical Emission Spectroscopy (GDOES) measures the thickness and composition of the zinc coating correctly, accurately and with good repeatability. This paper aims to verify the possibilities of the RF-GDOES for analysis of alloy coatings with non-conductive surface treatment. By comparing the results of RF-GDOES analysis and EDX microanalysis carried out using SEM, it was found that both methods provide the same values of the chemical composition of the base material and the alloy coatings, as well as the thickness of the alloy coatings.

Adhesive bonding is a method often used for bonded joints of aluminum alloys preparation. The surface pre-treatment is strongly influencing bonded joints shear strength. The surface of two aluminum alloys (AlMg3, AlMgSi) subjected for bonded joints preparation were surface pre-treated using one commercially used and two laboratory prepared solutions. Scanning electron microscopy including chemical composition analysis and tensile shear test for analysis of the pre-treated aluminum alloys were used. Surface of both the examined alloys after pre-treatment exhibited similar character regardless analyzed material and used pre-treatment solution. Tensile shear test revealed differences between individual solutions used for material surface-pretreatment. AlMgSi alloy reached higher shear strength then the AlMg3 alloy. Exposure of the bonded joints to the climate conditions simulated in a climate chamber revealed and decisive influence of the environment to the adhesive properties of individual materials, however, also differences in the used adhesives were observed and were shown to be more significant than the pre-treatment conditions.

In this paper, the preparation and characterization of as-deposited and heat-treated low phosphorus Ni-P coatings on AZ91 magnesium was performed. Heat-treated Ni-P coatings reached the higher microhardness of 1030 ± 20 HV 0.025 when compared to as-deposited Ni-P coatings (560 ± 20 HV 0.025). Using the scanning electron microscopy, the microstructure and surface morphology of Ni-P coatings was observed. Heat-treated coatings were formed by cracks network on their surface due to their crystallization during the heat-treatment. These cracks negatively affected the electrochemical and corrosion properties. However, as-deposited Ni-P coatings improved the electrochemical corrosion properties when compared to AZ91 alloy. The corrosion potential increased to -0.59 ± 0.02 V and the corrosion current density decreased to 1.4 ± 0.3 µA∙cm 2.

The main topic of the paper is the roughness analysis of machined surfaces shaped parts and influences that affect them. Specifically, it is an analysis of selected 2D and 3D roughness parameters by using the 3-axis, 3+2-axis and 5-axis milling methods. In order to analyse the life of components and performances, the key requirement is the evaluation of surface roughness. In terms of 2D roughness, the most widely used parameters are Ra, Rz and Rq. In the case of 3D roughness, namely Sa, Sz and Sq parameters. The current trend leads to continuous improvement measurement methods and instruments. Evaluation of Surface roughness involves various contact and noncontact methods. For this experiment, the material of aluminium alloy EN AW-6060 - AlMgSi0, 5 F19 was chosen. Sample sizes 40x40x25mm were selected. Samples were made on a universal 5-axis milling machine DMG MORI specifically DMU 50 with the Heidenhain iTNC 530 control system. The Milling centre is located in the laboratories of the Department of Machining, Assembly and Engineering Metrology of the Technical University of Ostrava. Surface roughness analysis was performed on a three-dimensional Alicona InfiniteFocus G5 microscope. With this optical meter, the surface topography was analysed in view of 2D and 3D surface roughness and waviness.