Influence of Surface Preparation and Heat Treatment on Mechanical Behavior of Hybrid Aluminum Parts Manufactured by a Combination of Laser Powder Bed Fusion and Conventional Manufacturing Processes

Abstract

Today, in industry, laser-based additive manufacturing (LAM) is used to produce high-value parts of very complex designs that are not manufacturable by conventional technologies; this process’ low production throughput and high cost prevent it from being used more extensively. One way to exploit the benefits of LAM in industry is to have it combined with lower-cost manufacturing technologies. In a hybrid approach, LAM can be integrated within an assembly line’s welding station to complete the manufacturing of a product by depositing a foreign material on a substrate only where needed, or by building structures of complex 3D geometries (e.g., lattice structures) directly onto inexpensive preforms. To pave the way for using a hybrid approach design in real applications, as a prime requirement, the chosen technology must grant comparable structural integrity to its products with respect to its conventional counterparts. In this work, different types of surface pretreatments for substrates were investigated as a key enabling factor to tailor the bi-material system’s mechanical properties in use. Hybrid samples were made by depositing AlSi10Mg by direct metal laser sintering onto A356-T6 aluminum bases prefabricated by casting and forging, and their properties were compared with fully homogeneous samples that were conventionally produced. Specifically referring to the automotive use case, both these alloy grades were chosen for their extensive use in the production of motor vehicles. The testing campaign, characterized by microscopy, mechanical testing, and fatigue, revealed that the structural integrity of the hybrid samples is comparable with the benchmarks when standard heat treatments are adopted. This result makes the prospect of the exploitation of the hybridization concept as conceived very promising for the future.

Build Plate Roughness Study on Part Bonding for the Laser Powder Bed Fusion Process

“…This finding suggested potentially strong default adhesion at the early bonding stage. Our findings align with and expand upon the work of Tommassi et al, 30 who explored the influence of preform surface treatments on joining properties in direct metal laser sintering, highlighting the potential significance of substrate engineering for adhesion enhancement. Similarly, Mouchard et al 31 observed, using a laser-blown powder process, that blasting surface preparation significantly impacted fabrication, influencing the single-track geometry and promoting larger, deeper welds.…”

Effects of Curing on Photosensitive Resins in SLA Additive Manufacturing

“…It has rich potential for many other applications, such as wearable devices with different bodily functions [6] or other biomedical applications, e.g., custom-made implantable devices. On the other hand, the factors majorly limiting the use of AM are the low production throughput and its related costs [7]. In addition, due to variations in the manufacturing processes, the 3D printed objects might have different dimensions than the CAD models.…”

“…In turn, these geometrical properties can improve the engineering performance of a component. Moreover, AM can reduce the "cradle-to-gate" environmental footprint of component manufacturing through the avoidance of the tools, dies, and materials scrap associated with subtractive processes [7]. This allows for low-waste, sustainable design strategies.…”

Sol–Gel Silica Coatings for Corrosion Protection of Aluminum Parts Manufactured by Selective Laser Melting (SLM) Technology

“…SLM technology is used to produce high-value parts with very complex designs, which cannot be made with conventional technologies; the high cost of this process prevents its extensive use in industry, but combined parts made in AM with parts made with conventional technologies at low production costs make its use in industrial production possible, making hybrids that use AM technology only where it is really needed [19].…”