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

The work is dedicated to the study of the properties of detonation coatings AlB12-30 wt.% Al (AB70) applied to Steel 45 using the DNEPR-5M installation. The coatings have the following characteristics: thickness h ~ 170-200 μm, Hμ = 27-29 GPa, HV = 4.35 GPa. Changes in the tribological characteristics of the composite depending on the friction mode are analyzed. The AB70 coating is found to have stable tribological characteristics: f = 0.21-0.38, wear rate I = 3.3-8.6 μm/km. Samples with coatings exceed uncoated Steel 45 in wear resistance. Changes in the surface structure after friction depending on the sliding speed and load are shown. Two wear mechanisms – oxidative and adhesive-abrasive – are established. A conclusion was drawn regarding the possibility of using the AlB12-Al system to apply detonation coatings.

A laser-induced oxidation method for the formation of a TiO2 layer on a Ti substrate was used. The TiO2 phase can be controlled by an Nd:YAG laser with fundamental frequency at an intensity I = 52.8 MW/cm2 and three different doses. Dose D1 = 3.1×1020 phot/cm2 forms a TiO2 layer in the anatase phase, which possesses the highest photocatalytic, antibacterial and adhesion properties. As the laser dose increases, the TiO2 layer thickness increases from 40 nm to 100 nm, but the photocatalytic decomposition reaction constant decreases. The observed super-linear increase of the TiO2 layer thickness with the laser dose is explained by the presence of positive feedback during the irradiation process. The temperature rises with increasing of the thickness due to the interference-caused decrease of the reflection coefficient. As the thickness increases, TiO2 on Ti structure adhesion decreases from 800 mN to 400 mN due to the formation of a layer with a mixture of phases.

Despite the rapid development of metallurgical processes for the production of semi-finished products aimed at improving the modes of smelting, casting and crystallization, a significant improvement in the properties of any cast metal, ensuring its wide application in modern mechanical engineering, is achieved by combined thermomechanical processing of workpieces, combining hot metal forming and heat treatment. The technologies and equipment currently used in Kazakhstan by machine-building manufacturers have long been obsolete and ineffective. A common problem for everyone is the high energy intensity of production, its low productivity and the quality of forgings and blanks produced, which leaves much to be desired. Namely forgings and blanks are the starting materials for the manufacture of highquality tools and technological equipment at mining and metallurgical engineering enterprises. Therefore, the purpose of this work is to develop rational modes of thermal and thermochemical processing of 5KHV2S steel, previously forged in a tool that implements alternating strain in metal, as well as to study the influence of combined thermomechanical processing modes on the mechanical properties of this steel. The studies carried out in this work on the hardness of 5KHV2S steel samples subjected to combined thermomechanical processing showed that the developed technologies contributed to an increase in both total and surface hardness compared with samples not subjected to preforging in a new forging tool that implements alternating strain in the metal.

The main groups of factors / soil-climatic, agrotechnical, technological and organizational / influencing the quality of the main and pre-sowing tillage of the soil and the relationships between them are examined.
The results obtained show that compliance with the main groups of factors and good organization of work improve the quality of the main and pre-sowing tillage, reduce the costs of their implementation and increase yields.

Despite the rapid development of metallurgical processes for the production of semi-finished products aimed at improving the modes of smelting, casting and crystallization, a significant improvement in the properties of any cast metal, ensuring its wide application in modern mechanical engineering, is achieved by combined thermomechanical processing of workpieces, combining hot metal forming and heat treatment. The technologies and equipment currently used in Kazakhstan by machine-building manufacturers have long been obsolete and ineffective. A common problem for everyone is the high energy intensity of production, its low productivity and the quality of forgings and blanks produced, which leaves much to be desired. Namely forgings and blanks are the starting materials for the manufacture of highquality tools and technological equipment at mining and metallurgical engineering enterprises. Therefore, the purpose of this work is to develop rational modes of thermal and thermochemical processing of 5KHV2S steel, previously forged in a tool that implements alternating strain in metal, as well as to study the influence of combined thermomechanical processing modes on the mechanical properties of this steel. The studies carried out in this work on the hardness of 5KHV2S steel samples subjected to combined thermomechanical processing showed that the developed technologies contributed to an increase in both total and surface hardness compared with samples not subjected to preforging in a new forging tool that implements alternating strain in the metal.

In this paper, the results of Shore D hardness and tensile strength according to ISO 10319 were investigated. The results were processed statistically by creating a trend line and regression analysis in order to study in details the existing relationship

Modern armor steels are essential in safeguarding military and civilian assets from ballistic threats. This paper provides a comprehensive classification of contemporary armor steels, examining their material properties, including hardness, impact resistance, and the influence of chemical composition, particularly carbon equivalent (CE), on their performance. The classification considers chemical composition, alloying elements, and mechanical properties, with a focus on their ballistic effectiveness and suitability for various armored platforms. Additionally, the paper delves into the historical evolution of armor steel, tracing its origins from early military applications to the sophisticated alloys used today. It also highlights the importance of MIL-DTL specifications in establishing a standardized language for armor steel grades, ensuring uniformity in quality and performance across the defense sector. Furthermore, the paper discusses the role of heat treatment procedures, such as quenching and tempering, in influencing the microstructure and mechanical properties of armor steels, directly affecting their resistance to penetration and impact. Through a review of armor steel classifications, historical context, and their technological advancements, this paper offers valuable insights into the ongoing efforts to improve the performance and reliability of armored materials.

In this article, the maximum tensile strength and hardness of 3D printed samples of Nylon CF15 Carbon were investigated. 20 test specimens were produced with dimensions according to the ASTM D 638 standard for tensile strength and 3 specimens for Shore D hardness testing. The experimental results were processed statistically.

The article investigates the influence of technology and technological parameters of manufacturing on the structure, phase composition and physical and mechanical properties of the Fe-FeCr800 composite system. It was established that the determining factor in phase and structure formation is the manufacturing technology, while vacuum sintering and hot forging have their own optimal technological parameters. At the same time, hot forging makes it possible to obtain a composite with a higher microhardness of structural components due to a change in the content of component components. The results of the research also showed that the preheating time (for 20 min.), as well as thermomechanical treatment, is sufficient for the phase formation process, in particular, with the release of carboboride phases of the type Me3CB and Me3(CB)2, while the densification processes are intensified, which makes it possible to obtain a material with lower residual porosity. Analysis of mechanical tests showed that vacuum sintering makes it possible to obtain composites with higher mechanical properties due to the active interaction between the components of the composite. However, high-temperature annealing after hot deformation will allow for a composite with high mechanical properties.

Pelton mini hydro-turbine, more concretely its turbine circle buckets was completely damaged during explotation conditions i.e. working time of about two years and half. Because turbine was ensured in ensured company, representatives of the company engaged court expert prof Cvetkovski to perform investigations (analysis) and to determine the reasons for these accidents. Normally working time of the Pelton turbine is about ten years, but there is examples that it can work even twenty years if construction and maintains of turbine was properly done. Therefore, the purpose of the conducted expert examination is to analyze the causes, effects and potential solutions for the damaged Pelton turbine. This report covers the technical aspects, the mechanisms that contribute to the appearance of defects, that is, damage of the buckets of the Pelton turbine. In order to find the reason of failure of the turbine buckets, as first complete visual inspection of the turbine wheel was performed. As additional investigation was performed chemical analysis of the buckets, measuring of its hardness and metallographic investigation (determination of type and quantity of non-metallic inclusion and microstructure).

This paper investigates the influence of aging parameters (temperature and time) on thermal, mechanical and structural properties of the EN AW-6060 aluminum alloy. Thermal diffusivity and hardness were measured after applied heat treatments followed by investigation on scanning electron and transmission electron microscopes. Heat treatments included: solutionizing at 550°C for 1 hour followed by quenching in ice water; after quenching samples were aged at two separate temperatures of 180°C and 200°C for 1-8 hours. The results show that hardness gradually increases with aging time achieving peak value of 95 HV10 after aging at 180°C for 5 hours. Thermal
diffusivity also increases with both aging time and temperature achieving peak values after aging at 200°C for 4 hours. SEM/EDS analysis show the existence of finely distributed precipitates containing Mg, Si and Fe. TEM investigation confirms the existence of rod-shaped precipitates several nanometers in length.

Mechanical tests of 5- and 6-component high-entropy alloys, which were obtained for the first time by the method of hot forging, were carried out. The test results showed a fairly high hardness and strength of the obtained alloys. The TiCrFeNiC alloy (without annealing) has the highest mechanical properties. Its high strength is due to solid-solution hardening, as well as the formation of carbides in situ. Fractographic studies showed mostly quasi-brittle destruction of alloy samples.