This article provides an overview of Direct Energy Deposition – Arc technology (DED-Arc), also known as Wire Arc Additive Manufacturing (WAAM), which involves the deposition of metal wire using an arc power source and a CNC or robotic manipulator. The high deposition rate of WAAM justifies its use for the manufacturing of small to large-size components with lower resolution and less complex geometry. However, the use of wire as feedstock in the WAAM process has certain advantages and disadvantages, which are explained in detail. The WAAM specialties are in-situ alloying and the production of functionally graded materials (FGMs). Various sensors, path planning, process control, and FEM simulation from WAAM are used to reduce material and energy consumption and make the process more sustainable. Post-processing techniques are also discussed as a method of improving the quality of the final product. Finally, the prospects of the WAAM process are presented.

Nanostructured adhesives represent a paradigm shift in bonding technology, leveraging the unique physicochemical properties of nanoscale materials to enhance adhesive performance. This review examines the fundamental principles underlying nanostructured adhesive design, focusing on the role of nanoparticles, nanofillers, and nanocrystals in improving mechanical properties. Furthermore, this paper will explore the diverse applications of nanostructured adhesives across industries, including aerospace, automotive, electronics, and biomedicine, highlighting the potential for tailored adhesive solutions.

Directed Energy Deposition (DED) processes offer the advantage of producing larger parts with higher deposition rates compared to Powder Bed Fusion (PBF) additive manufacturing (AM). However, DED typically results in simpler geometries and lower resolution. When using Wire and Arc- based DED, even larger components can be manufactured at an accelerated rate, but the higher heat input may lead to undesirable microstructures, adversely affecting mechanical properties. To ensure defect-free depositions, precise process control is essential, including optimizing deposition paths, regulating inter-layer temperature, and maintaining a consistent nozzle-to-layer distance. One effective approach to improving material integrity is the application of in-situ vibrations during deposition. This technique helps reduce porosity and grain size while also enhancing surface waviness and mitigating residual stress buildup. Further refinement of material properties can be achieved through appropriate thermo-mechanical processing, leading to mechanical characteristics comparable to conventionally produced steel. This paper explores the impact of in-situ vibrations and heat treatment through case studies, analysing their effects on surface waviness, residual stress distribution, porosity, microstructure, grain size, mechanical properties, and fracture toughness. The findings demonstrate the significant benefits of these process enhancements in improving the mechanical performance of DED- fabricated components.

The paper presents the method of using the solution selection method in developing a new concept of the BOBCAT E62 excavator control handle, with the aim of implementing a lightweight design. The lightweight design concept is used in various industries, including the design, i.e. construction of construction machinery, where the use of modern materials and design methods can lead to an optimal solution, while maintaining load-bearing capacity and functionality. The modified handle design solution aims to reduce weight, without major changes to other parts of the assembly of which it is a component. Two methods were used to assess the concept selection, as an integral part of the product development process, i.e. the solution selection phase. The selected concept solution should contribute to improvements in terms of durability, compactness and reduced energy consumption.

Additive manufacturing enables the production of parts with complex geometries that would be difficult or impossible to produce with conventional manufacturing technologies – and with minimal waste. A more massive use of additive technologies makes it possible to shorten supply chains and reduce the need to store parts. Fixtures are essential production aids that position, hold and support workpieces, ensuring positioning accuracy, repeatability and operator safety during assembly and bonding. This paper presents how the Fused Deposition Modeling (FDM) process can provide such fixtures for the adhesive bonding of metal parts in rail vehicle composite structures. By adapting geometry, surface properties and ergonomics to the bonding task at hand, FDM fixtures improve alignment accuracy and simplify handling.

This study explores an innovative method to enhance Directed Energy Deposition (DED) of aluminum 5356 products by integrating an electromagnetic vibration system into the DED setup. The application of vibrations significantly improved surface quality, reducing surface waviness and increasing building efficiency by 14%, from 78.5% to 92.25%.Gas porosity was reduced from 1.5 ± 0.04% in as-built (AB) components to 0.34 ± 0.07% in vibration-assisted (VA) parts. Tensile tests showed a marked reduction in anisotropy, with the tensile strength deviation between the x and z directions decreasing to less than 0.4% for vibration-assisted samples, compared to 7.9% for asbuilt ones. Additionally, secondary phase analysis revealed a homogenization effect, with magnesium- and iron-rich precipitates displaying a finer dispersion (3.57 ± 3.42 µm²) compared to 11.28 ± 12.49 µm² in as-built parts. Overall, the findings highlight the potential of vibration-assisted DED to improve part properties, reduce defects, and advance the DED manufacturing process.

The aim of this work is to study joining Al 2024-T3 alloy plates with different welding procedures. Aluminum alloy AA 2024-T351 is especially used in the aerospace industry. Aluminum plates are welded by the TIG and MIG fusion welding process, as well as by the solid-state welding process, friction stir welding (FSW), which has recently become very important in aluminum and alloy welding. For welding AA2024-T35 with MIG and TIG fusion processes, the filler material ER 4043—AlSi5 was chosen because of reduced cracking. Different methods were used to evaluate the quality of the produced joints, including macro- and microstructure evaluation, in addition to hardness and tensile tests. The ultimate tensile strength (UTS) of the FSW sample was found to be 80% higher than that of MIG and TIG samples. The average hardness value of the weld zone of metal for the MIG- and TIG-produced AA2024-T3511 butt joints showed a significant decrease compared to the hardness of the base metal AA2024-T351 by 50%, while for FSW joints, in the nugget zone, the hardness is about 10% lower relative to the base metal AA2024-T3511.

Adhesive bonding has proven to be a reliable method of joining materials, and the development of new adhesives has made it possible to use bonding in a variety of applications. This article addresses the challenges of bonding metals such as the aluminum alloy EN AW-5754 and the stainless steel X5CrNi18-10. In this study, the effects of laser cleaning and texturing on the surface properties and strength of two bonded joints were investigated and compared with mechanical preparation (hand sanding with Scotch-Brite and P180 sandpaper). The bonded joints were tested with three different epoxy adhesives. During the tests, the adhesion properties of the bonded surface were determined by measuring the contact angle and assessing the wettability, the surface roughness parameters for the different surface preparations, and the mechanical properties (tensile lap-shear strength). Based on the strength test results, it was found that bonded joints made of stainless steel had 16% to 40% higher strength than aluminum alloys when using the same adhesive and surface preparation. Laser cleaning resulted in maximum shear strength of the aluminum alloy bond, while the most suitable surface preparation for both materials was preparation with P180 sandpaper for all adhesives.

Use of composite materials has seen significant growth, especially in the manufacture of lightweight structures and biomedical applications. One type of composite material is made up of polymer materials reinforced with glass fibres. PA6-GF reinforced with 25 % chopped glass fibres is a representative of this composite material group. The manufacturer recommends annealing as a heat treatment process after production. However, annealing requires additional equipment and time. This paper seeks to investigate the effect of non-annealed PA6 GF on the Charpy impact properties. Samples for Charpy impact property tests are defined according to BAS EN ISO 179-2:2021. The test specimens were printed on the FlashForge Creator 3 PRO printer, and the testing was performed on the AMSLER RPK300 device.

Adhesive bonding is a well-established technique for joining materials. This article deals with the challenges of bonding metals, such as aluminium alloy EN AW-5754. To improve the strength of bonded joints, suitable surface preparation prior to bonding is essential. In this work, the surface of the aluminium alloy using three different epoxy adhesives was subjected to two different methods of surface preparation, such as laser cleaning and sanding by hand with sandpaper. The adhesion properties of the bonded surface were determined by measuring the surface roughness parameters (Ra and Rz) for different surface preparations as well as the mechanical property (tensile lap-shear strength). It was found that the bond strength of the aluminium alloy changed depending on the surface preparation and adhesive used, indicating that using the same adhesive and material with different preparation methods can lead to significant variations in bond strength. Therefore, choosing an appropriate surface preparation method that is suitable for the parts to be bonded and their surface roughness is crucial as it increases the strength of the bonded joints.

The additive technologies such as 3D printing are an important part of all branches of industry, primarily due to the possibility of production parts with complex geometries. The aim of the research presented in this paper is the analyze of joining 3D printed polymer parts with adhesive. Furthermore, the aim of this research is to analyze the strength of lap adhesive joints under different loads. FDM technology, PLA materials and two-component epoxy adhesive were used to fabricate the testing specimens.

This paper aims to present the effects of the MIG welding on the mechanical properties of a buttwelded joint of dissimilar aluminium alloys 2024-T351 and AA 6082-T6. Aluminium alloy 6082 T6 is well weldable by classical fusion welding processes (MIG and TIG), while aluminium alloy 2024-T351 is almost non-weldable. For the welding of these two Al alloys, the MIG welding was used on an 8 mm thick sheet using filler material 4043A (AlSi5) and a mixture of argon and helium as a shielding gas. The influence of MIG welding on the obtained structure and mechanical properties of the welded joint was analyzed. The assessment of the mechanical properties of the welded joint of dissimilar Al alloys was performed by Vickers hardness testing, tensile and bending tests of the welded samples.

Sustainable joining technologies are important manufacturing processes for the production of high-quality joints of electrical connections. High-quality connections must have high electrical and thermal conductivity to reduce energy losses during their lifetime, they must have high mechanical properties to achieve a long service life, and they must be manufactured with lower energy consumption. In this article, the properties of solid wire electrical contacts produced by ultrasonic welding and soldering were compared. Ultrasonic welding of thin solid copper wires was performed with a copper ring. A particular focus of this study is on the energy used to produce these joints. The research included electrical resistance, peel strength and tensile strength tests, The results of the electrical resistance showed similar electrical resistance between the two processes. The result of mechanical strength shows that ultrasonic joints achieved higher mechanical strength. The most important result is that ultrasonic welding consumed only 11% of the energy to produce the joint compared to soldered joints.

This paper aims to compare the mechanical and structural properties of butt-welded properties of dissimilar aluminum alloys 2024-T351 and AA 6082-T6 obtained by MIG and TIG welding processes. Alloy AA 6082 T6 is well weldable by classic fusion welding processes (MIG and TIG), while alloy 2024-T351 is almost non-weldable. For the welding of these two different Al alloys, MIG and TIG welding procedures were used on 8 mm thick sheet metal using additional material 4043A (AlSi5) and a mixture of argon and helium as a protective gas for the MIG welding process, or pure argon for the TIG welding process. The paper compares the mechanical properties of welded joints obtained by MIG and TIG welding. The microstructural evolution of the welded joint of dissimilar aluminum alloys AA6082-T6 and AA2024-T351 is compared. The mechanical properties of welded joints of dissimilar aluminum alloys are compared based on the results of Vickers hardness tests, tensile and bending tests of welded samples.

Multi-material design was developed as a modern design concept for lightweight structures (Lightweight design - LW) which aims to integrate different types of materials into one structure. The main problem when joining sheets made of different, i.e. dissimilar materials, primarily steel and aluminum alloys, are the different mechanical, physical and chemical properties of the materials being joined. Through this paper, the state of the art will be analyzed when it comes to modern technologies for joining steel and aluminum alloys sheets. The term "modern joining technique" refers to all innovative joining technologies that have been developed or have seen significant application in the last few years.