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

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.

Recovering antimony from secondary sources is increasingly important to ensure a sustainable and secure supply of this critical metal. Industrial residues, waste materials, and by-products offer opportunities for recycling and reprocessing, reducing economic dependence on primary ores. This paper reviews potential waste streams and processing methods for achieving high-yield antimony recovery.

This study investigated the effect of cold plastic deformation at Bridgman anvil chamber temperature on the hardness and wear resistance of X160CrMoV12 steel using hardness testing, X-ray diffraction (XRD), abrasive grinding wear (AEMW) testing, optical examination, and scanning electron microscopy (SEM). Three batches of samples were prepared for the experiment: I – hardened, II – hardened and then tempered at 600°C for 1.5 hours, III – hardened and then plastically deformed. The samples were hardened at three temperatures: 1100, 1150, and 1200 °C. The highest amount of retained austenite, reaching 69.02%, was observed when hardening at 1200°C, while at lower temperatures, 17.36% and 38.14% were formed, respectively. After hardening (batch II), the amount of retained austenite decreased proportionally by approximately 7 times for each hardening temperature. The effect of plastic deformation (batch III) is observed by analysing the hardness of samples from the surface to the depth, reaching an average hardening depth of 0.08 mm. To check how well it holds up to wear, the surfaces of three test batches were tested using an abrasive grinding test with a load of 5N. Hardened and plastically deformed specimens showed greater resistance to abrasion than hardened and tempered specimens. The results confirmed that the optimal hardening temperature for achieving maximum wear resistance of this steel is 1100°C.

The application of laser technology across manufacturing, from automotive to aerospace, has been a key driver of modern industrial efficiency. However, traditional laser processes often rely on static parameters and manual oversight, which can lead to inconsistencies and defects. The recent integration of artificial intelligence (AI) and machine learning (ML) is fundamentally transforming this landscape, moving laser processing from a static, pre-programmed task to a dynamic, self-optimizing system.

The work aimed to evaluate the effect of microalloying titanium in proportions of 1 to 5 wt.% on the microstructure and microhardness of a precipitation-hardenable martensitic stainless steel. The standard chemical composition of martensitic steel 17-4PH was used, to which 1; 2; 3; 4 and 5 wt.% Ti was added, respectively. Microstructural analyses revealed changes in the crystal grains and precipitation effects from the solid solution of the alloy. Microhardness measurements were also performed, which demonstrated that withincreasing Ti content in the alloy the metallic matrix becomes harder. The study confirms that microalloying with Ti is beneficial for the development of martensitic stainless steels to increase mechanical properties, even without the application of subsequent heat treatments.
The results obtained in this work represent a starting point for the development of new customized alloy recipes, adapted to specific applications, where a high value of hardness, as well as microstructural stability or wear resistance are required.

This study examines how thermal and mechanical effects influence hardness distribution in 4, 6, and 8 mm AA5754 aluminum plates welded using TIG with AC and DC currents. Vickers hardness (HV0.01) was measured alongside tensile tests to evaluate weld performance. Results show that AC welding produces higher but more variable hardness, while DC welding yields more stable profiles. Notably, thinner plates (4 mm) showed minimal hardness differences between current types due to faster cooling. Strain hardening increased hardness up to 125 HV and reduced variation. The extent of hardness stabilization and heat-affected zone size depended on plate thickness. Although current type influenced hardness distribution, it had little effect on fracture toughness.

Electromagnetic radiation in space presents a significant challenge to the durability of aluminum alloys used in spacecraft construction. This study analyzes the effects of ionizing radiation (gamma rays, cosmic rays, solar particles), ultraviolet and solar radiation, electromagnetic pulses (EMP), and extreme temperature fluctuations on a novel composite material based on AA7075 (B95) aluminum alloy. The results demonstrate that prolonged exposure of the material in outer space (28 months) leads to structural changes and alterations in mechanical properties. To ensure the reliability of the results, the space-exposed samples were compared with reference samples stored under terrestrial conditions.

The contact interaction between the metal matrix composite based on Ti64 and the B4C-based composite was investigated. It is shown that the interaction process is influenced by the annealing temperature and holding time. The phase that formed independently of the contact pair is TiB. However, the thickness of the products formed at the boundary depends on the contact pair. In case of the Ti64-B4C pair the thickness is 70 μm, while for (Ti64-40 wt% TiC)-B4C it becomes 10 μm. This significant difference in the thickness is due to the presence of refractory particles (TiC) in (Ti64-40 wt% TiC)-B4C couple, because the TiC phse reduce the diffusion of Ti into the contact zone.

The effect of individual additions of Ti and B into high chromium white cast irons (HCWCIs) on the structure, corrosion and selected mechanical properties was investigated. Two different heat treatments were applied, high-temperature treatment at 960 oC/1h, and subcritical treatment at 550 oC/4 h. The microstructure was investigated by OM and SEM; compositions of matrix and carbides were analyzed by EDS. Mechanical behavior of HCWCIs was analyzed by measuring hardness, toughness, abrasive/wear resistance and resistance to repeated impacts. Corrosion behavior was evaluated electrochemically, by linear and Tafel polarization methods in 0,1M NaCl solution. The properties of the modified HCWCIs were compared with the properties of the base unmodified HCWCI alloy (ASTM A532-IIE).

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.

Titanium–titanium boride (Ti/TiC) metal matrix composites have been widely identified as promising materials for various applications. The traditional ingot metallurgy processing strategies used to fabricate these materials are energy intensive and have fallen short of their perceived mass production potentials. Powder metallurgy processing of Ti/TiC composites from titanium and TiC powder blends, is currently widely used for the cost-efficient production of such composites. Additional processing by the method of hot pressing improves the structure and mechanical properties of this class of materials. The composites have the heterogenous microstructure with areas high hardness area over 1173 HV. While matrix and inclusions had the value of 700 HV.

This work examines the relationship between two of the most important mechanical parameters: shear and tensile strength in 3D printed polymer test specimens using Fused Deposition Modeling. Different types of materials were used, including those that are mechanically strong, easy to print, flexible, and heat-resistant, to determine their behavior. The study was conducted by testing test specimens printed with the same characteristics of percentage filling and pattern, layer height, and printing direction. The ratio between the shear strength and tensile strength of seven polymer materials with 30 % infill in percent was calculated. The values were compared with those of metals and polymers with 100 % density, and an estimate of the coefficient between the two parameters was made.