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

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.

Defects in die castings can include underfilling, blistering, sticking to the mold, and cracking. However, the factor that most affects the quality of castings is porosity. The primary causes of porosity are gaseous impurities and improper mold venting, which lead to gaseous porosity. Additionally, a poorly selected gating system, low casting speed, excessively short piston paths, low post-pressure, and low casting temperatures all contribute to shrinkage porosity. An additional factor contributing to the occurrence of pores is the increasing proportion of scrap (from production and post-production), which contains a wide variety of impurities. Gaseous inclusions (e.g., hydrides) can be removed from the liquid alloy by refining it, but metallic impurities are worse. In Al-Si alloys, one of the most detrimental elements is iron, which enters solution due to its low solubility in the solid state, at levels exceeding 0.6 wt%. At high percentages, it crystallizes in morphologically unfavorable phases, which deteriorate service properties, increase brittleness and porosity of castings, and limit their use.
This paper presents the results of a study of the effect of increased iron content (from 0.8wt.% to 1.5wt.%, in 0.2wt.% increments) on the porosity of AlSi7Mg alloy die castings. Porosity evaluation, conducted using microscopic metallography methods, was performed both qualitatively and quantitatively. It was found that the unfavorable morphology and dimensions of the Al5FeSi phase hinder the free flow of liquid alloy at the crystallization front. The lamellar-ligneous separations “close” the space between the dendrites of the α(Al) solid solution, causing the formation of shrinkage porosity. Increasing the iron content of die-cast Al-Si alloys forces the use of higher doping pressures, but not enough to cause “ejaculations” of the alloy in the dividing plane of the casting mold.

Aluminum alloys are critical in industries such as aerospace and automotive due to their lightweight, strength, and corrosion resistance. Optimizing their properties is challenging and benefits from advanced predictive tools. This paper explores the use of mathematical modeling in understanding and designing aluminum alloys. Techniques like thermodynamic modeling (e.g., CALPHAD), phase transformation kinetics, and mechanical property simulations are reviewed. Computational methods, including finite element analysis and machine learning, are highlighted for their roles in alloy design and manufacturing, such as casting and additive manufacturing. Comparisons between model predictions and experimental results demonstrate accuracy and limitations. Applications in optimizing material properties and improving manufacturing processes are discussed. By accelerating alloy development and enabling tailored properties, mathematical modeling emerges as a transformative tool, advancing aluminum alloy research and driving innovation across industries.

This paper examines corrosion protection techniques for aluminum alloys, focusing on traditional and innovative surface treatment methods. Aluminum alloys are applicable in many industries due to their advantages derived from the good combination of chemical, physical, and mechanical properties. However, they are susceptible to various forms of corrosion, which can critically compromise the structure of the component and lead to damage that does not ensure safe operation. Coatings are necessary for the durability and effective protection of aluminum and its alloys from corrosion, ensuring safe and long-term operation of components in aggressive environments.

Digital image correlation tests were performed during cold deformation on aluminum – magnesium alloy. The comparison of strain distribution obtained with 2D and 3D digital image correlation was analyzed and compared. The comparison of strain distribution in static tensile tests was performed with qualitative strain distribution and quantitative line analysis and strain-time relationship. The tests showed that there were no significant differences in the strain values and distributions obtained using the 2D and 3D digital image correlation when comparing the qualitative and quantitative results.

The paper focuses on the application of friction stir welding (FSW) technology for welding of unequal materials based on aluminum alloys. Joints were made from AW 5083 and AW 6082 materials using FSW technology at different weld speed values. The joints were analyzed metallographically, the hardness of the materials was tested across the cross section of the joint and the strength of the joint was tested by destructive static tensile test. At the lowest weld speed, the materials were not perfectly mixed, there was a macroscopically visible gap at the joint location, which was reflected in the lack of joint strength. At the medium and highest weld speed values, a joint with mechanical properties comparable to those of the base material was formed. Metallographically, the bond between the materials was free of any internal defects.

The aim of this paper is the investigation of the effect of natural aging on the mechanical, physical and microstructural properties of an EN AW-6060 aluminum alloy. These properties were investigated during different aging treatments. Firstly, the effect of natural aging on properties was investigated, after which the influence of natural aging (room temperature pre-aging) on the artificial aging was studied. The results showed the beneficial effect of natural aging in both sets of experiment. During the natural aging, the hardness increased for around 20 % while electrical conductivity values were slightly higher than in the quenched sample. The hardness of the samples gradually increases up to 25 days of natural aging reaching a plateau state, after which the values of hardness remain the same. Also, room temperature pre-aging had a positive effect on subsequent artificial aging. Samples that were pre-aged for 40 days or more before artificial aging had around a 13 % increase in hardness values compared to the samples that were directly artificially aged. Electrical conductivity had increased by around 1 MS/m in pre-aged samples compared to only artificially aged samples. Optical microscopy investigations confirmed the existence of precipitated phases and their distribution in the microstructure.

This work is focused on investigation of different thermomechanical treatment (TMT) regimes influencing mechanical and electrical properties of Al-Mg-Si alloy. Three TMT regimes were chosen, which differ in the number of treatment steps. Grain size, microhardness, electrical conductivity were measured. It was revealed that dividing TMT into 2 stages favorably affects formation of mechanical and electrical properties in Al6101.

At present time there is considerable interest in extending the application area of low-alloy and rather inexpensive heat- hardenable aluminum Al-Mg-Si alloys in the automotive industry, aviation, construction and electrical engineering. In this regard, the topical problem is to enhance strength and electrical conductivity of such materials, which would subsequently reduce the weight of products made of structural and electrical Al-Mg-Si materials. Severe plastic deformation is one of the promising methods of obtaining a significant increase in properties. In this paper a new SPD method is investigated – Multi-ECAP-Conform, characterized by the fact that per one processing cycle the accumulation of true strain is provided up to е>2.5. In order to study the stress-strain state effect on the mechanical properties of the aluminum Al-Mg-Si alloy, mathematical and physical modeling with the modern software Deform-3D were applied, as long as the well-established techniques of assessment of materials mechanical characteristics after plastic processing. The obtained results demonstrate the adequacy of using mathematical and physical modeling to estimate the stress- strain state by Multi-ECAP-Conform.

This paper presents the results of the computer and experimental study of a promising technique of severe plastic deformation (SPD) – Multi-ECAP-Conform (M-ECAP-C) for the fabrication of long-length nanostructured billets (wire rods) with an enhanced strength and electrical conductivity from the aluminum alloy EN-AW 6101 in a single processing cycle. On the basis of the obtained results, a new rational geometry of the pressing channel for the M-ECAP-C technique has been developed. The stress-strained state, structure and mechanical properties of pilot samples of wire rods have been studied. It has been established that processing by the new technique leads produces enhanced mechanical and physical properties.