Concrete reinforced with two or more different types of fibers, rationally combined, is known as Hybrid Fiber-Reinforced Concrete (HFRC). This composite material offers enhanced properties, particularly in terms of ductility and crack control. Its application in drainage pipes, as a partial or total replacement for conventional reinforcement, may have a positive impact on the precast industry from both technical and economic perspectives. HFRC can be produced and cast in molds, similarly to traditional concrete. The reinforcing fibers are added to the mix like any other aggregate, allowing for the elimination of traditional steel mesh reinforcement and simplifying the production process. This study presents the numerical simulation of the Three-Edge Bearing Test (ASTM C497) to evaluate the mechanical behavior of Class II reinforced concrete pipes (RCPs) according to ASTM C76, and hybrid fiber-reinforced concrete pipes (HFRCP). HFRC, composed of steel and polypropylene fibers, is modeled as an equivalent homogeneous material with average properties (macroscopic model). The problem is solved using a nonlinear finite element code that incorporates a constitutive model with coupled damage and plasticity. Finally, numerical results are compared with experimental data obtained from a testing campaign involving six HFRCPs produced and tested with two different hybrid fiber dosages. The numerical model reasonably reproduces the bearing capacity and deformation of both HFRCPs and RCPs, considering the large number of variables involved.

This study investigates the electrochemical performance of a Ti–10Mo alloy fabricated via Laser Powder Bed Fusion (LPBF) for potential biomedical implant applications. The alloy was engineered to improve corrosion resistance, while the LPBF technique enabled the production of dense, fine-grained structures suited for implantation in corrosive physiological environments. Microstructural characterization revealed the presence of partially unmelted molybdenum particles retained within the matrix, which was consistent with tomography analysis. The incomplete melting is attributed to the significantly higher melting point of molybdenum (2623 °C) compared to titanium (1668 °C), along with differences in laser absorptivity and thermal conductivity, particularly under insufficient energy input during LPBF processing. To evaluate corrosion behavior under simulated physiological conditions, potentiodynamic polarization tests were performed in 0.9% NaCl solution after 48 hours of immersion. The LPBF-processed Ti–10Mo alloy exhibited a corrosion potential (E_corr) of –0.17 V, a corrosion current density (I_corr) of 34.48 nA/cm², and a polarization resistance (Rp) of 345.94 kΩ·cm². In contrast, commercially pure titanium displayed E_corr = –0.44 V, I_corr = 494.73 nA/cm², and Rp = 61.52 kΩ·cm². These results indicate that the LPBF-fabricated Ti–10Mo alloy demonstrates a significantly more noble electrochemical potential, a lower corrosion rate, and a substantially higher resistance to charge transfer, highlighting its suitability for long-term biomedical implant applications.

This research focused on characterizing an Inconel 718 (IN718) nickel-based super alloy fabricated via Direct Metal Laser Sintering (DMLS), specifically examining the impact of homogenization, solution, and aging treatment on grain structure, crystallographic texture, precipitate formation/dissolution, and material hardness. Studies have revealed that as-printed IN718 exhibits a microstructure defined by extremely fine columnar or cellular dendrites with laves phase precipitates forming at both grain boundaries and inter-dendritic areas; this contrasts with the microstructure of cast materials and necessitates a unique heat treatment regimen distinct from conventional methods. The findings indicate that the homogenization process at 1080°C, combined with solution treatment at 980°C, as well as aging treatment at both 720°C and 620°C, is sufficient to drastically alter the grain structure as printed and eliminate the segregates and Laves phase, resulting in noticeable modifications to the crystallographic texture and grain structure. The hardness level rose by 51-72% relative to the as-printed state, and this increase was largely caused by the formation of γ', γ" phases within the γ-matrix, which occurred following the heat treatment. This study conducts a thorough examination and analysis of the as-built sample and the sample treated with heat under various conditions, such as the laser power, scanning speed, and layer thickness, which are established to govern the manufacturing process and subsequently dictate the microstructure, ultimately affecting the mechanical properties, including the tensile strength, yield strength, impact strength, and hardness.

One very promising method of imparting additional functional properties to aluminium products is to modify the surface of an aluminium alloy by anodic oxidation and impregnation of a porous oxide layer, thereby obtaining superhydrophobic properties.
The methods presented in this study involved a few steps. First, the substrate material was subjected to abrasive blasting to obtain a rough surface. Samples mechanically prepared with three different grades of roughness were then anodically oxidised to produce a thick (≈20 µm) oxide coating with adsorption properties. The adsorption properties of the oxide coating were then used to saturate the pores with a 10% PTFE aqueous suspension, diluted from a 60% commercial solution. This process resulted in an oxide coating with a developed surface area, which gained superhydrophobic properties after impregnation in a PTFE suspension. Anti-icing properties were also tested, and accelerated ageing tests were carried out in a climate chamber. The results obtained were analysed in light of the correlations between wetting angles, freezing delays of water droplets and the surface roughness profiles of the substrates, as well as corrosion resistance. Corrosion resistance was evaluated using Electrochemical Impedance Spectroscopy (EIS).
The combination of abrasive blasting, anodic oxidation and PTFE impregnation treatments resulted in hydrophobic and superhydrophobic surface properties. The best results for delaying water droplet freezing were obtained for the smooth surface sample, which also revealed the best corrosion resistance. After cycles of testing in a climate chamber, the hydrophobic and superhydrophobic properties of the surface did not decrease and were also characterised by very high corrosion resistance compared to pure aluminium after the anodic oxidation process.
The best results for delaying water droplet freezing were obtained for the smooth surface sample, which also revealed the best corrosion resistance.

Laser Powder Bed Fusion (L-PBF) has been recognized as a key additive manufacturing (AM) technique for the fabrication of complex metal components. Despite its advantages, the process has been affected by inherent defects such as porosity, which have been shown to influence mechanical properties and part reliability significantly. In this study, 316L stainless steel alloyed with 2.5 wt% copper was fabricated using L-PBF, and its porosity and relative density were analyzed under a wide range of processing parameters. A comprehensive evaluation was carried out using three distinct techniques: optical microscopy (OM), Archimedes density measurements, and X-ray computed tomography (XCT). These methods were employed to analyze pore morphology, including size, shape, and spatial distribution. The primary objective was to perform a comparative analysis of the precision and applicability of each technique for this specific alloy, which had not been extensively studied. In this study, relative density varied from 95.45% at high VED values to 99.04% in optimized conditions, highlighting the strong influence of processing parameters on defect content.The results revealed differences among the methods: XCT provided volumetric insight into internal porosity, OM offered high-resolution 2D surface analysis, and the Archimedes method was found to be sensitive to open pores and surface-connected defects. While XCT detected relative densities up to 99.04% with precise pore morphology classification, the Archimedes method slightly underestimated density in samples with surface-connected defects, and OM showed higher variability due to its 2D limitation. XCT revealed that pores with sphericity ≥0.45 and compactness ≥0.2 dominated in high-density samples, whereas irregular pores were more prevalent under excessive energy input. The study highlighted the importance of choosing suitable evaluation methods for analysing defect content in additively manufactured parts and demonstrated the influence of processing parameters on porosity characteristics.

The surface modification and anodization behavior of Ti6Al4V (Ti64) alloy components produced by electron beam powder bed fusion (EB-PBF) were investigated to enhance their compatibility for biomedical applications. Ti64 samples were fabricated using optimized EB-PBF parameters to achieve a uniform microstructure and surface finish. Anodization was performed at 40 V and 60 V, resulting in the formation of self-organized TiO₂ nanotube arrays. Subsequently, a heat treatment at 550 °C was applied to improve the crystallinity of the nanotubes while preserving their structural integrity. Surface morphology and topography were characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM), revealing voltage-dependent variations in nanotube thickness and surface roughness. Phase composition analysis using X-ray diffraction (XRD) confirmed the formation of anatase TiO₂. Mechanical properties were evaluated using nanoindentation and nanoscratch techniques, showing higher hardness and improved adhesion in samples anodized at 40 V, attributed to their denser nanotube structure. Electrochemical testing demonstrated a significant enhancement in corrosion resistance in anodized samples compared to their untreated parts. Furthermore, in vitro bioactivity analysis confirmed increased apatite formation on anodized surfaces, indicating an improved biological response. These findings demonstrate that the combination of EB-PBF and controlled anodization presents an exciting approach for modifying the surface properties of Ti64 parts, thus improving their mechanical performance, corrosion resistance, and bioactivity for biomedical applications.

The manufacture of hulls for small boats requires a thorough knowledge of the hull manufacturing field, hull materials, and the damage that hulls may encounter during maritime navigation (such as cracks or wear caused by shock or collision, etc.). Materials such as wood, aluminum, stainless steel, and composite materials are used to manufacture these hulls. This work was interested in the manufacturing of layered composite materials; these are lightweight, less expensive, more hermetic, and more resistant. The main objective of this work is to manufacture a part of the hull of a small boat using composite materials. Also, testing the mechanical strength of the manufactured sample constitutes a second objective of this work. In this work, a boat hull sample was manufactured using composite materials (glass fiber mat E-type with polyester resin). Calculation of fiber and resin quantities was performed to manufacture a sample with a thickness equal to 4 mm. A visual analysis of the defects obtained on the manufactured sample, and the identification of their causes, were performed in this work. Several mechanical tests were performed to measure the permeability, hardness, and Young's modulus of the tested specimens. The results obtained show that the mechanical properties of the layered sample respect maritime safety rules and the rigour required during boat construction.

Wire arc additive manufacturing (WAAM) is an additive technology in which a metal wire is melted with an electric arc, and the parts are formed layer by layer. Austenitic stainless steel wires are promising materials in the manufacture of parts via WAAM. Austenitic steels have good ductility and corrosion resistance, but low strength. Nitrogen alloying, which leads to solid-solution hardening, can increase strength. In addition, austenitic stainless steels are sensitive to the formation of hot cracks during welding, which can be corrected by the low content of δ-ferrite in the structure of such steels.

In this work, a flux-cored wire was developed using WAAM, which ensures the formation of an austenitic–ferritic structure of the deposited metal. The chemical composition of the deposited metal was as follows: wt. %: 0.055 C; 0.43 Si; 5.0 Mn; 20.1 Cr; 4.1 Ni; 2.1 Mo; 2.9 Cu; 0.319 N.

The characteristics of the WAAM product made from developed flux-cored wire were compared with the properties of AISI 321 steel. The deposited layers of the experimental composition were characterized by greater microhardness and improved strength characteristics, with a slight decrease in plastic properties, compared with AISI 321 steel. In addition, the developed material surpasses AISI 321 steel in terms of the pitting potential in artificial seawater. The phase composition of the deposited layers is deformationally stable: no austenite–martensite phase transformation was detected in tensile plastic deformation tests.

This research was carried out with the support of a grant from the Russian Science Foundation (RSF) No. 24-19-20059 (https://rscf.ru/en/project/24-19-20059/) and the Government of the Sverdlovsk Region.

Owing to their cost-effective and comprehensive physical and chemical properties, steels are often utilized as structural materials in the construction of bridges, industrial equipment, marine vessels, and offshore platforms. Most of these steels are central components of load-bearing applications, which are usually exposed to harsh corrosion environments such as marine atmosphere, acid fog, and polluted industrial corrosive effluents. Conventional methods rely on coatings such as painting, electroplating, or galvanizing, which involve operational complexities, high costs, and environmental concerns. A potential solution to these disadvantages involves improving their inherent corrosion resistance through the refinement of the grain structure of alloy steels. In this study, the possibility of graphite solution as a quenchant for steel is explored. Since graphite has an excellent thermal conductivity of 2000 W/m K compared to water's conductivity of 0.598 W/m K, its quenching characteristics show promising results. In this study, the corrosion resistance of the steel samples was evaluated under both stagnant and flow-accelerated conditions. The graphite-quenched samples consistently demonstrated superior corrosion resistance compared to the water-quenched ones, particularly in a flow-accelerated environment. Microstructural analysis supported these findings, showing reduced surface degradation in graphite-quenched specimens. The Tafel plot analysis further confirmed the results, with the lower corrosion current density of graphite-quenched samples being shown in both stagnant and flow-accelerated conditions. Moreover, the graphite-quenched samples had a more positive corrosion potential, which indicates their greater electrochemical stability. This research highlights the potential of graphite-based quenchants as viable alternatives for applications that require enhanced corrosion resistance, without significantly compromising hardness.

Industry 4.0, the fourth industrial revolution, is focused on the complete digitalisation of manufacturing, and has been spearheaded by the development of direct digital manufacturing technologies, such as selective laser melting and extruder-based 3D printing. As a consequence, there is the possibility Tthat significant changes will be made to the way in which products are designed and fabricated. In particular, these approaches can take advantage of digital optimisation processes such as topology optimisation. As an example, the form of a particular product can be optimised against a specific property, such as mass, as additive manufacturing allows materials to be placed at any point in the volume. We can easily envisage that the target function in the optimisation could involve other properties such as carbon footprint and the possibility of recycling or composting. These powerful optimisation processes are unlocked within the context of digital manufacturing if the complete chain is digital. As a result, in the design and fabrication cycle, the material selected for that product will naturally play a critical role in determining the properties of the final product. Some additive manufacturing technologies are able to fabricate in a straightforward and controlled manner, with spatial variations in properties. Taking advantage of these developments would provide additional advantages to digital fabrication technologies. This work is focused on developing a framework for handling materials within digital manufacturing processes to enable advances in a digital manner as described above. It is particularly challenging to identify a single framework which is suitable for all types of materials, including metals, ceramics, glass and polymers, although to do so would be especially advantageous with respect to the optimisation of products with regard to sustainability. This work proposes that the coordinate space of materials only makes sense if it is related to what is available in the specific manufacturing process.