Nowadays, the use of metal processing additive technologies is a rapidly growing field in the manufacturing industry. These technologies, such as metal 3D printing (also known as additive manufacturing) and laser cladding, allow for the production of complex geometries and intricate designs that would be impossible with traditional manufacturing methods. They also offer the ability to create parts with customized properties, such as improved strength, wear resistance, and corrosion resistance. In other words, these technologies have the potential to revolutionize the way we design and produce products, reducing costs and increasing efficiency to improve product quality and functionality. One of the significant advantages of these metal processing additive technologies is a reduction in waste and environmental impact. However, there are also some challenges associated with these technologies. One of the main challenges is the cost of equipment and materials, which can be prohibitively expensive for small businesses and individuals. Additionally, the quality of parts produced with these technologies can be affected by factors such as printing speed, temperature, and post-processing methods. This review article aims to contribute to a deep understanding of the processing, properties, and applications of ferrous and non-ferrous alloys in the context of SLM to assist readers in obtaining high-quality AM components. Simultaneously, it emphasizes the importance of further research, optimization, and cost-effective approaches to promote the broader adoption of SLM technology in the industry.

ElectroSpark Deposition (ESD) is a pulsed micro-welding process that is capable of depositing wear and corrosion resistance deposit to repair, improve, and to extend the service life of the components and tools. Major new applications have taken place in gas turbine blades and steam turbine blade protection and repair, and in military, medical, metal-working, and recreational equipment applications. In this study, the ESD technique was exploited to fabricate 2024 aluminum alloy deposit on a similar substrate. The deposits were deposited using different process parameters. Heat input was varied on three levels. The outcoming microstructure was analyzed by optical and scanning electron microscopies. The deposit was characterized by the overlapping of layers with a mixed microstructure. The average hardness was independent from the process parameters. Both porosity inside the deposits and cracks at the deposit/substrate interface were detected. The porosity lowered with the heat input and increased the average length of cracks.

In this study, the effect of increasing exposure time on the microstructures, porosity, mechanical properties and corrosion behavior of selective laser melted sample Al-Si10-Mg powder was investigated. The samples were processed at the same power (375 W) and scan speed (2000 mm/s), but with increasing exposure time. Exposure time equal to 40, 50 and 60 µs was applied. The features of the analyzed samples show that with increasing exposure time, greater efficiency of the heat input was obtained, with a larger size of the melt pool and Si particles and lower porosity. Specifically, at the highest exposure time the melt pool showed an increase of 19% in width and 48% in depth, while the volume percentage of the voids decreased by 50% with respect to the lowest exposure time. Moreover, with the coarser microstructure being associated with a lower level of voids, the average hardness is similar for the analyzed samples. Corrosion resistance was evaluated, being one of the most important properties that may affect the service performance of Al-Si10-Mg alloy in the aerospace, marine and automotive industries. The potentiodynamic curves of the samples show that the voids occurrence is more significant with respect to the scale of the microstructure on corrosion behavior, with the sample processed at the highest exposure time being the more resistant to corrosion. The experimental techniques used in the present study were Optical Microscope (OM), Scanning Electron Microscope (SEM), hardness and X-Ray Computed Tomography.

Despite the advantages of powder bed fusion–laser beam (PBF-LB), Ti6Al4V components often exhibit high yield strength but limited ductility, which restricts their use in critical structural applications. This study aims to identify the most effective heat treatment to optimize the strength–ductility balance in Ti6Al4V parts produced by PBF-LB and to establish direct correlations between microstructural states, mechanical properties and corrosion behavior. Two distinct post-processing heat treatments were applied, specifically, the first at 500 °C for 5 h and the second at 800 °C for 2 h, both followed by air cooling. The microstructure was characterized using optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Mechanical behavior was assessed through Vickers microhardness testing and tensile testing, while corrosion resistance was evaluated via electrochemical measurements. Residual stress profiles were determined using the hole-drilling strain gauge method, in both as-built and heat-treated conditions. The as-built samples displayed a fully martensitic α′ structure with columnar grains aligned parallel to the laser scanning direction, resulting from rapid solidification. Heat treatment at 500 °C caused only partial decomposition of acicular martensite into substructures without altering its acicular morphology, leading to a strengthening effect alongside a reduction in ductility. Conversely, heat treatment at 800 °C offered the most balanced combination of strength and ductility among the conditions studied, albeit with a moderate reduction in corrosion resistance.