International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

This study presents a comparative analysis of three types of coatings taken from the active area of the coted harrow disks using atmospheric plasma spray deposition method (APS). The resulting coatings increase the durability of the harrow discs and the inclusion in the componence of coatings of carbides and powdered ceramic compounds will enhance the mechanical characteristics. This study focused on scanning electron microscopy of the coated samples from the harrow discs and their tribological properties. SEM imaging and EDS analysis have been carried out to clarify the morphological characteristics and study of disc cross-section. Tribological tests were carried out to determine the following main parameters: adhesion to the substrate, coefficient of friction (COF), modulus of elasticity and hardness of the material.
The development and implementation of modern technologies for improving the mechanical and chemical properties of materials for
coated harrow discs will increase resistance to abrasive wear in modern agricultural conditions.

The article examines the morphology of high-entropy coatings formed using vacuum technologies on low-carbon steel substrates. Studying the morphology of the surface layers of TiAlSi (N ,C ) coatings formed on low-carbon steel substrates using atomic force and optical microscopy methods made it possible to establish the dependence of the morphological parameters of the coatings on the energy parameters and chemical composition of the substrate. The dependence of the morphological parameters of coatings on the conditions for the formation of vacuum layers on low-carbon steel substrates is also shown.

The physic-technological basis for fabrication of bulk rods and plates of amorphous, amorphous-nanocrystalline and 100% nanocrystalline alloys at melt cooling rates from 80 to 3200 K/s with crystal sizes from 10 to 50 nm has been developed. The multiphase structure formed in the initial bulk samples, as well as in the process of nanocrystallization of amorphous ribbons, is characterized by record microhardness values of 17-22 GPa. Amorphous powders (20-100 μm) of Fe55Ni8Co6Mo4Cr2V1Al2P9C6B5Si2 and Fe61.37Co6.84Cr3.78V0.85W0.82Mo1.06Nb0.85B19.87C1.99Si2.57 alloys are used to create a wear-resistant coating on structural stainless steels and low-carbon St3 by the gas-thermal “cold” method » sputtering and subsequent melting of the applied layer.The values of microhardness (Hμ) of nano-coatings significantly exceed the microhardness of all known tool steels. Examples of technology transfer and practical using of developed amorphous and nanocrystalline alloys are presented.

Nanotechnology has grown in popularity due to the enormous potential for producing materials and products with diverse properties, allowing significant advancement of existing technology and the development of new innovative technologies. Nanomaterials behave differently at the nanoscale than their conventional counterparts, opening exciting new possibilities in a wide range of construction applications. Nonetheless, the lack of information on nanomaterials’ suitability, high costs, and health risks limits their use in construction and structural engineering. As a result, research must be conducted to provide accurate information and facts about the properties and performance of nanomaterials under various load conditions, as well as information on the advantages of using nanomaterials over other construction materials. This paper provides information on nanomaterial properties and how they affect structural materials’ microstructure and mechanical properties. It also demonstrates the benefits of using nanotechnology and suggests new possibilities.

The morphology of the coatings has a significant effect on the tribological characteristics of the contacting bodies. Depending on the relief of the surface layers of the coatings, the resistance of the modified substrates to corrosion is dete rmined. It is known that the processes of friction and corrosion have a decisive influence on the performance of products. To reduce the influence of these processes, various protective coatings are used, including those formed by the method of electrospark alloying. The aim of th is work was to study the morphology and structure of electrospark coatings formed by layer-by-layer electrospark alloying. In the course of the studies carried out, it was found that these coatings are morphologically heterogeneous, with a large number of cracks and splats.

Recent research has shown that the Nano coating materials play a vital role in improving performance of corrosion resistance in hostile environment and enhancing the mechanical properties and reducing the dimension changes. Due to the superior capabilities of Nano coating in many benefits which can be achieved, in addition to corrosion resistance, mechanical properties, make it smoother, stronger and improves its adhesive properties. In this work, the effect of anti-corrosive nanomaterials (Cobalt and Zinc) coating on chemical corrosion behavior and mechanical properties of carbon steel cylindrical pipe were studied in detail. The Nano-coating was done with different thicknesses (300nm,600nm,900nm and 10 μm), then analyzed using ANSYS software technology (version .19).The results showed that there is a strong relationship of corrosion improvement with improving mechanical properties, especially surface deformation resistance, elastic strain and stresses reduction of the inner pipe surface which contains a pressurized corrosive fluid. The maximum improvement was with the thickness of the cobalt coating (10 μm. The result of improvement in corrosion resistance of the cobalt-coated surface is approximately (5.165%) compared to the uncoated surface, also, the results showed an improvement in mechanical resistance and corrosion res istance because of deposition of cobalt particles better than zinc particles in all different thicknesses, with a maximum of about (66%) compared to zinc. Therefore, can conclude that the improving corrosion resistance due to coating with nanomaterials is very promising.

The part-2 research is a continuation of part-1 of using a simulation of Nano coating effect on linearized stresses resistance using Finite Element Analysis (FEA) software was carried out. The prime focus here was on exposing a thin Aluminum (Al7075-T6) walled spherical vessel to internal pressure before and after coating, this spherical vessel was coated by Nano- layer using two different materials such as Titanium (Ti) and Nickel (Ni) with thicknesses ranging (100 nm, 500 nm, and 900 nm). Then a comparison of the obtained results was made before and after coating. The results showed that the aluminum Al7075-T6 thin walled spherical vessel successfully coated with Titanium and Nickel separately using ANSYS software. In addition, the results have shown that 100,500 and 900 nm thickness Nickel coated aluminum 7075-T6 thin walled spherical vessel has a better improvement in linearized stresses resistance. These improvements in linearized stresses resistance were equal to 42% with Nickel coating in comparison with Titanium coating of thickness (100, 500 1nd 900 nm). The improvement of the linearized stress highest resistance is about 2.5% and 5% for Ti and Ni, respectively.

The protective coatings of Al2O3 and AlN on iodide titanium in initial state and after annealing in a hydrogen atmosphere were investigated by scanning electron microscopy. It was found that the coatings protect titanium from the interaction with hydrogen at a pressure of 0.6 MPa up to 650 °C. It was shown that at 700 °C and pressure 0.6 MPa cracking of the protective coatings occurred, and the process of active absorption of hydrogen started.

The use of an advanced nanotechnology coating process is absolutely helpful in immensely optimizing the efficiency of mechanical properties of materials such as: Longer service life, ability to tolerate greater loads, ease and low cost of maintenance, the environmental gain in the conservation of resources, improved response in kinetic systems, lower energy consumption, resistance to corrosion, low friction, use of low-cost base material, etc. Metal materials are usually subjected to various surface conditions that might cause stress, strain, deformation, and corrosion. Accordingly, Nano-coating technology is used to enhance the performance of mechanical properties in addition to reduce mechanical failure as much as possible. This research, a simulation of Nano coating effect on some mechanical properties performance using Finite Element Analysis (FEA) software was carried out. The prime focus here was on exposing a thin Aluminum (Al7075-T6) walled spherical vessel to internal pressure before and after coating, this spherical vessel was coated by nano- layer using two different materials such as Titanium (Ti) and Nickel (Ni) with thicknesses ranging (100 nm, 500 nm, and 900 nm). Then a comparison of the obtained results was made before and after coating, the results showed that the aluminum 7075-T6 thin walled spherical vessel was successfully coated with Titanium and Nickel separately using ANSYS software. Also the results showed that 900 nm Nickel coated aluminum 7075-T6 thin walled spherical vessel has a better improvement in mechanical properties. These improvements in mechanical properties were varied between 4.5225% to 20.724% depending on coating thickness and coating material. The Nickel coating has shown higher improvements in comparison with Titanium were observed.

In this study, the stress state of metal coating on a steel substrate under tensile straining was investigated by with finite element modelling with the aim of better understanding the mechanism of delamination for the coating. The investigations showed cracking and delamination of the coating by the application of uniaxial tensile strain to the substrate. Due to interfacial stress crack appeared in the coating-substrate interface. The stress measurements in coated substrate, using FEA, indicated interfacial shear and peeling stresses at the interface near the edges of the coating under tensile load. When tensile stress is applied externally on the coated substrate, the coating exhibits multiple cracking perpendiculars to the tensile direction, and then interfacial debonding occurs. A good agreement is found between the modelling approach and the corresponding experimental tensile tests of the coated specimens. The effect of coating thickness on the evolution of the stress distribution was also studied. The cracking and delamination of the coatings with a thickness ranging from 90 to 160 m was studied by tensile test experiments. The estimation of the stress distribution and concentration at the interface during these experiments allows the failure stress of the coating in the interface coating–substrate to be evaluated.

The structure and physicomechanical characteristics of vacuum coatings formed from refractory metal compounds on steel substrates of different chemical composition are studied. The possibility of applying refractory metal coatings to protect metal substrates used for the manufacture of metalworking tools and steel tools used for casting non-ferrous metals has been analyzed.

Electrochemical behavior of silver in tungstate-molybdate melts was studied by potentiometric and voltammetric methods. The electrode process was identified as a single-electron reversible one. The effect of silver on the electrochemical deposition of molybdenum carbide coatings and their electrochemical corrosion behavior in a sodium polysulfide melt was studied.