Effects of Laser-Deposited Maraging Steel on L-PBF 316L Component

Abstract

The capabilities of additive manufacturing (AM) techniques have been extensively examined in the literature. However, scientific gaps persist on the feasibility of realizing a coated component manufactured by using various materials processed by combining different AM processes. From this perspective, this study focuses on the manufacturing of a directed energy deposition (DED) coating by using 18Ni (300) maraging steel powder on AISI 316L components realized by laser-powder bed fusion (L-PBF), in order to assess the production of components with high geometrical complexity combined with high mechanical surface properties in selected areas. The quality of the manufactured coatings was assessed in-process through the implementation of an optical monitoring system and real-time image processing. In addition, an in-depth metallurgical analysis (microstructural and chemical) of the interface between the DED coating and the L-PBF component was carried out. Finally, hardness tests were performed on both the as-deposited and heat-treated coatings to confirm the high mechanical performance of the final component surface. The results revealed the potential of producing cost-effective and geometrically complex parts, such as molds or tools with internal cooling channels, that implement mechanically high-performance surfaces.

Residual stress evaluation in innovative layer-level continuous functionally graded materials produced by Powder Bed Fusion-Laser Beam

“…1), were heat treated to improve the mechanical properties of the martensitic steel. In accordance with previous studies in the literature [41,48,49], a solution annealing treatment was performed at a temperature of 815°C for 1 hour followed by air cooling, and then an aging treatment was performed at a temperature of 480°C for 5 hours followed by air cooling. Figure 2 shows a photograph of the specimens produced.…”

“…The chemical composition of both, shown in Table 1, was provided by the manufacturers. Additional information regarding the investigated materials can be found in the study [41]. To study the evolution of residual stresses in components made of cFGMs within the same layer, four parallelepiped-shaped specimens with dimensions of 75x10x12 mm were fabricated.…”

“…De Baere et al in [64] noted that for a nominal power density similar to that used in this work, an effective laser power of about 50 W, which is de ned as the product of the nominal laser power and the laser absorption coe cient (between 0.3 and 0.5 for 18Ni Maraging 300 [65, 66]), results in the development of a tensile stress eld on the surface. Consequently, a subsequent heat treatment is necessary to induce the austenite-martensite transformation, which enhances the surface hardness [41] and modi es the residual stress state of the component.…”

Metallic Coatings through Additive Manufacturing: A Review

“…The metallic coatings produced through additive manufacturing technologies are not limited to high-end alloys, i.e., Ti6Al4V [ 153 , 218 ], stainless steels [ 112 , 156 ], AlSi10Mg [ 219 , 220 ], Maraging steels [ 221 , 222 ], CoCrMo [ 145 ], and Ni-based alloys (IN718, IN625, etc.) [ 213 , 223 ].…”