Influence of oxygen content on melt pool dynamics in metal additive manufacturing: High-fidelity modeling with experimental validation

Chia, Hou Yi; Wang, Lu; Yan, Wentao

doi:10.1016/j.actamat.2023.118824

Cited by 38 publications

(8 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These rapid solidification structures are found everywhere in the material, including near the surfaces. However, as-built surfaces are known to be more complex due to the presence of secondary phases 17 , 18 .…”

Section: Introductionmentioning

confidence: 99%

Critical role of slags in pitting corrosion of additively manufactured stainless steel in simulated seawater

Sen-Britain,

Cho,

Kang

et al. 2024

Nat Commun

View full text Add to dashboard Cite

Pitting corrosion in seawater is one of the most difficult forms of corrosion to identify and control. A workhorse material for marine applications, 316L stainless steel (316L SS) is known to balance resistance to pitting with good mechanical properties. The advent of additive manufacturing (AM), particularly laser powder bed fusion (LPBF), has prompted numerous microstructural and mechanical investigations of LPBF 316L SS; however, the origins of pitting corrosion on as-built surfaces is unknown, despite their utmost importance for certification of LPBF 316L SS prior to fielding. Here, we show that Mn-rich silicate slags are responsible for pitting of the as-built LPBF material in sodium chloride due to their introduction of deleterious defects such as cracks or surface oxide heterogeneities. In addition, we explain how slags are formed in the liquid metal and deposited at the as-built surfaces using high-fidelity melt pool simulations. Our work uncovers how LPBF changes surface oxides due to rapid solidification and high-temperature oxidation, leading to fundamentally different pitting corrosion mechanisms.

show abstract

Section: Introductionmentioning

confidence: 99%

Critical role of slags in pitting corrosion of additively manufactured stainless steel in simulated seawater

Sen-Britain,

Cho,

Kang

et al. 2024

Nat Commun

View full text Add to dashboard Cite

show abstract

“…Compared to this simplified model, consideration of thermal-fluid interaction improves the melt pool prediction, as demonstrated by Robichaud et al 25 . It is understood that the primary driving force for convection was Marangoni flow which results in both inward and outward 26 flow at the surface of the melt pool. Neglecting this Marangoni flow leads to an overestimation of the melt pool depth.…”

Section: Introductionmentioning

confidence: 99%

Physics guided heat source for quantitative prediction of IN718 laser additive manufacturing processes

Amin,

Li,

et al. 2024

npj Comput Mater

View full text Add to dashboard Cite

Challenge 3 of the 2022 NIST additive manufacturing benchmark (AM Bench) experiments asked modelers to submit predictions for solid cooling rate, liquid cooling rate, time above melt, and melt pool geometry for single and multiple track laser powder bed fusion process using moving lasers. An in-house developed Additive Manufacturing Computational Fluid Dynamics code (AM-CFD) combined with a cylindrical heat source is implemented to accurately predict these experiments. Heuristic heat source calibration is proposed relating volumetric energy density (ψ) based on experiments available in the literature. The parameters of the heat source of the computational model are initially calibrated based on a Higher Order Proper Generalized Decomposition- (HOPGD) based surrogate model. The prediction using the calibrated heat source agrees quantitatively with NIST measurements for different process conditions (laser spot diameter, laser power, and scan speed). A scaling law based on keyhole formation is also utilized in calibrating the parameters of the cylindrical heat source and predicting the challenge experiments. In addition, an improvement on the heat source model is proposed to relate the Volumetric Energy Density (VEDσ) to the melt pool aspect ratio. The model shows further improvement in the prediction of the experimental measurements for the melt pool, including cases at higher VEDσ. Overall, it is concluded that the appropriate selection of laser heat source parameterization scheme along with the heat source model is crucial in the accurate prediction of melt pool geometry and thermal measurements while bypassing the expensive computational simulations that consider increased physics equations.

show abstract

“…The simulations confirm and clarify the observed variations in weld bead geometry that arise due to very different flow patterns. These differences result from the marginal fluctuations in the chemical composition within the tolerance of the standard defining the material composition of a special alloy [17]. C. R. Heiple et al [18] confirmed that the addition of small concentrations of a surface active element (Se) to stainless steel dramatically increased the D/W ratio of a severely defocused and decoupled laser weld.…”

Section: Introductionmentioning

confidence: 99%

Effect of Microchemistry Elements in Relation of Laser Welding Parameters on the Morphology 304 Stainless Steel Welds Using Response Surface Methodology

et al. 2023

View full text Add to dashboard Cite

Small differences in the contents of surface active elements can change flow direction and thus heat transfer, even for different batches of a given alloy. This study aims to determine the effects of sulfur on weld bead morphology in the laser process. The paper presents the results related to the weld bead shape of two thin AISI 304 industrial stainless steel casts. One cast contains 80 ppm (0.008%) of sulfur, considered as a high sulfur content, and the other one contains 30 ppm (0.003%) sulfur, which can be considered low sulfur. The welds were executed using a CO2 laser. The effects of laser power (3.75, 3.67, 6 kW), welding speed (1.25, 2.40, 2.45, 3.6 m/min), focus point position (2, 7, 12 mm), and shield gas (Helium, mixed 40% helium + 60% argon and mixed 70% helium + 30% argon) with a flow rate of 10 L/min on the depth of the weld (D) and the aspect ratio (R = D/W) were investigated using RSM (response surface methodology). The experimental results show that the transfer of energy from the laser beam to the workpiece can be total in cases where the selected welding parameters prevent plasma formation. For the 304 HS cast, the focus point is the major factor in determining the depth of penetration, and its contribution is up to 52.35%. However, for 304 LS, the interaction between shield gas and focus point seems to play an important role, and the contribution of their interaction raises to 28% in relation to the laser depth of the weld. Moreover, the study shows that sulfur plays a surface-active role only in the case of partial penetration beads, so that a 56% partially penetrated weld supports the hypothesis of its surface-active role in the formation of the weld pool. However, a penetration of only 36% confirms the effects of a sulfur surface-active when the bead is fully penetrated.

show abstract

Influence of oxygen content on melt pool dynamics in metal additive manufacturing: High-fidelity modeling with experimental validation

Cited by 38 publications

References 63 publications

Critical role of slags in pitting corrosion of additively manufactured stainless steel in simulated seawater

Critical role of slags in pitting corrosion of additively manufactured stainless steel in simulated seawater

Physics guided heat source for quantitative prediction of IN718 laser additive manufacturing processes

Effect of Microchemistry Elements in Relation of Laser Welding Parameters on the Morphology 304 Stainless Steel Welds Using Response Surface Methodology

Contact Info

Product

Resources

About