Pool Surface Research Articles

LES of blockage of thermal radiation to the pool surface in large double pool fires.

Thermal radiation blockage to the pool surface plays a major role in assessing the fire growth and heat feedback to the pool surface and thereby intensity of pollution to the environment. In this work, large eddy fire simulations are performed to quantify the thermal radiation blockage to the pool surface of 0.6 m n-heptane double pool fires (DPF). The interspace between the two pools is varied from 0 to 0.6 m. The results of the air entrainment show that the considered double pool configuration is radiation dominated irrespective of the separation distances between the pools. The predicted heat feedbacks are in good agreement with the experimental results. A radiation influencing zone (RIZ) is introduced based on the percentage of the radiation contribution from the flame. RIZ is directly proportional to the flame height. Based on the opacity through the RIZ, the thermal radiation blockage is calculated. The blockage of radiation from standalone fire to double fire increased to 20%. The calculated radiative heat flux to the pool surface is in good agreement with the reported measurements. In addition, the maximum deviation between calculated and measured heat fluxes of the studied DPF is 6.8%. Further, the accuracy of the present methodology is shown better than the reported literature estimations.

Welding Defect Monitoring Based on Multi-Scale Feature Fusion of Molten Pool Videos.

Real-time quality monitoring through molten pool images is a critical focus in researching high-quality, intelligent automated welding. However, challenges such as the dynamic nature of the molten pool, changes in camera perspective, and variations in pool shape make defect detection using single-frame images difficult. We propose a multi-scale fusion method for defect monitoring based on molten pool videos to address these issues. This method analyzes the temporal changes in light spots on the molten pool surface, transferring features between frames to capture dynamic behavior. Our approach employs multi-scale feature fusion using row and column convolutions along with a gated fusion module to accommodate variations in pool size and position, enabling the detection of light spot changes of different sizes and directions from coarse to fine. Additionally, incorporating mixed attention with row and column features enables the model to capture the characteristics of the molten pool more efficiently. Our method achieves an accuracy of 97.416% on a molten pool video dataset, with a processing time of 16 ms per sample. Experimental results on the UCF101-24 and JHMDB datasets also demonstrate the method's generalization capability.

Effect of energy density on down surface characteristics of AlSi10Mg alloy fabricated via selective laser melting

The correlation between surface roughness and energy density in the down surface area of AlSi10Mg alloy manufactured by selective laser melting was analyzed. This study investigated the relationship between the contour melt pool shape and surface roughness in the down surface area across an energy density range of 10–150 J/mm³. As the energy density increased, the contour melt pool in the down surface area became more stable, which significantly influenced surface roughness. Low energy density resulted in the unstable formation of the contour melt pool, leading to a deterioration in surface quality, whereas high energy density promoted the stable formation of the melt pool. Sufficient energy density is essential for the complete formation of the contour melt pool on the down surface, which plays a crucial role in reducing surface roughness. However, within the energy density range where the contour melt pool is fully formed, keyhole defects may occur, and it can be anticipated that these defects may worsen at energy densities exceeding the critical threshold.

Research on the evolution mechanism of surface morphology and solidification crystallization simulation of molten pool in electron beam polishing

Clarifying the flow and solidification process rules of a molten pool in scanning electron beam polishing remains challenging. This paper establishes a geometric model that closely resembles the original milling morphology, investigates the morphology evolution process, the flow law of the molten pool, and the change in driving force under the action of the electron beam, and solves the solidification and crystallization parameters of the solid-liquid interface. Results demonstrate that thermocapillary force is the dominant driving factor for horizontal motion inside the molten pool, which immediately leads to the emergence of velocity conversion sites on the surface of the molten pool, thus effecting surface fluctuation variations. Combined with polishing inspection, the average surface roughness error is controlled within ±7 %. Solid-liquid interface deflection significantly affects grain growth, and solidification and crystallization parameters follow similar patterns at different workpiece speeds. The grain structure of the melt zone can be predicted with the crystallization parameters at various depths of the melt layer.

Study on the Influence of Laser Power on the Heat–Flow Multi-Field Coupling of Laser Cladding Incoloy 926 on Stainless Steel Surface

In order to explore the influence of laser power on the evolution of molten pool and convective heat transfer of laser cladding Incoloy 926 on stainless steel surface, a three-dimensional thermal fluid multi-field coupled laser cladding numerical model was established in this paper. The variation of latent heat during solid-liquid phase transformation was treated by apparent heat capacity method. The change in the gas–liquid interface was tracked using the mesh growth method in real time. The instantaneous evolution of temperature field and velocity flow field of laser cladding Incoloy 926 on a stainless steel surface under different laser power was discussed. The solidification characteristic parameters of the cladding layer were calculated based on the temperature-time variation curves at different nodes. The mechanism of the impact of laser power on the microstructure of the cladding layer was revealed. The experiment of laser cladding Incoloy 926 on 316L surface was carried out under different laser power. Combined with the numerical simulation results, the effects of laser power on the geometrical morphology, microstructure and element distribution of the cladding layer were compared and analyzed. The results show that with the increase in laser power, the peak temperature and flow velocity of the molten pool surface both increase significantly. The thermal influence of the molten pool center on the edge is enhanced. The temperature gradient, solidification rate, and cooling rate increased gradually. The microstructure parameters (G/R) are relatively small when the laser power is 1000 W. In the experimental range, the dilution rate and wetting angle of the cladding layer both increase with the increase in laser power. When the laser power is 1000 W, the alloying elements of the cladding layer are more evenly distributed and the microstructure is finer. The experimental results are in good agreement with the simulation results.

Numerical investigation of arc characteristics and metal properties in ELAMF-assisted WAAM with wire retraction

In this study, a multi-physics integrated model of wire arc additive manufacturing (WAAM) with wire retraction and external longitudinal alternating magnetic field (ELAMF) assistance is proposed and validated, and the effect of ELAMF on the arc plasma characteristics and metal properties are systematically and quantitatively investigated. The model comprehensively takes the arc plasma heating, wire dynamic retraction, droplet transfer, the formation and diffusion of metal vapor, the melting and solidification of molten metal, and the stirring effect of ELAMF into account. The simulated results show that ELAMF has compressed the arc morphology, and decreased the temperature, potential, current density and static pressure, which are most pronounced when the wire is at an elevated position and the transient current is at its peak phase. Meanwhile, the formation of low-temperature and low-velocity cavities in the center of arc column are promoted by ELAMF, consequently diminishing the energy transferred from the arc plasma to molten pool through thermal conduction and mitigating the squeezing of the arc plasma on the surface of molten pool. The results also demonstrate that the ELAMF has reduced the temperature gradient of liquid metal inside the molten pool, and intensified the forced convection for the occurrence of multiple circulations.

High-power fiber laser incident beam absorptivity variation of molten pool surfaces during their solid-liquid-gas state evolution

The thermal and ablation effects of lasers are widely used in laser additive manufacturing, laser welding, laser cleaning, and laser cladding technologies. Absorptivity is the core index of laser beam-thermal energy conversion efficiency. This paper analyzed the irradiated material's absorption behavior during the solid-liquid-gas evolution of laser-ablated metal surfaces by comparing the temperature fields and the corresponding weld cross-sections for different laser action periods, considering the fusion and vaporization latent heats. The solid-liquid-gas state evolution of high-power fiber laser-irradiated metal surfaces occurs during several milliseconds, with a short solid-phase existence period, since fusion or melting time is much shorter than the vaporization time. As the solid-liquid-gas state evolves, the average absorptivity and the share of thermal conduction energy loss decrease with the laser action time, while the fusion energy loss gradually increases. The solid-phase surface of the metal in laser processing absorbs significantly more incident laser energy than the liquid-phase one. The longer the solid-phase occurrence period of the metal surface during the laser action, the greater its average absorptivity of the incident laser. By increasing the laser spot area and scanning rate, the solid-phase period of the laser-irradiated metal surface can be increased, improving its incident laser absorptivity.

Detailed radiation modeling of two flames relevant to fire simulation using Photon Monte Carlo — Line by Line radiation model

This work reports benchmark data sets for radiative heat transfer in two distinct fire configurations obtained from the Measurement and Computation of Fire Phenomena (MaCFP) working group database. The cases include a 19.2 kW non-sooting turbulent methanol pool fire and a 15 kW sooting ethylene flame (referred to as the FM burner). The base configurations were simulated with large eddy simulation (LES) approaches using two different codes, namely FireFOAM and Fire Dynamics Simulator, respectively. Multiple frozen snapshots from these LES runs were radiatively evaluated using a photon Monte Carlo radiation solver and a line-by-line spectral model. The results were presented at three levels: Firstly, the radiative fields, including radiative emission, reabsorption, and heat flux contours, were shown. Secondly, the global radiative contributions from molecular gas species, soot, and wall boundaries were compared. Thirdly, a detailed spectral analysis of radiative fields for different components within five distinct spectral bands was presented. In the case of the non-sooting methanol pool fire, the radiative emission from CO2 predominates. However, for the radiation reaching the boundaries, both CO2 and H2O contribute almost equally. Conversely, for the sooty FM burner configuration, radiative emission from soot, CO2, and H2O all contribute similarly. In terms of radiation reaching the boundary, soot is the primary contributor in FM Burner. In the methanol pool fire, the pool surface receives a comparable contribution from CO2, H2O, and burner rim radiation, whereas, for the FM burner, the burner inlet surface primarily receives radiation from soot.

Interaction of contour and hatch parameters on vertical surface roughness in laser powder bed fusion

In Laser Powder Bed Fusion (L-PBF), surface roughness is pivotal for controlling the mechanical and functional performances, as well as the geometrical accuracy of the final product. This study extensively investigated the interactions of hatch and contour processing parameters, along with contour offset distance, on vertical surface roughness for 316L stainless steel in L-PBF. Melt pool morphology and surface arithmetic average roughness (Sa) were quantified using confocal microscopy, while scanning electron microscopy was employed to interpret the detailed microstructure of surface features. Under low volumetric energy density (VED) hatch conditions (e.g., 66.7 J/mm3), varying the contour offset distance has a negatable effect on the surface roughness when the contour VED is lower than 121.6 J/mm3, remaining relatively smooth surfaces dominated by bare melt tracks with sparely attached partially melted particles. Increasing the hatch or contour VED (e.g., 166.7 J/mm3), dross formation, identified by the microstructural differences and explained by the melt pool instability and migration, is inevitable, which dictates the surface roughness with higher Sa values. The larger contour offset distance further promotes the dross occurrence with irregularity and increases Sa. Employing a low contour VED with an appropriate offset distance and adopting the contour-first scan strategy was demonstrated as an effective solution to reduce the dross formation. Through the analysis of melt pool behavior, surface topography, and microstructure, this study elucidates the mechanisms governing dominant surface characteristics under the combined influence of hatch and contour parameters. It lays the foundation for precise control of surface roughness without altering hatching parameters, enabling the tailored manipulation of performance in additively manufactured structures.

Improved accuracy of continuum surface flux models for metal additive manufacturing melt pool simulations

Computational modeling of the melt pool dynamics in laser-based powder bed fusion metal additive manufacturing (PBF-LB/M) promises to shed light on fundamental mechanisms of defect generation. These processes are accompanied by rapid evaporation so that the evaporation-induced recoil pressure and cooling arise as major driving forces for fluid dynamics and temperature evolution. The magnitude of these interface fluxes depends exponentially on the melt pool surface temperature, which, therefore, has to be predicted with high accuracy. The present work utilizes a diffuse interface finite element model based on a continuum surface flux (CSF) description of interface fluxes to study dimensionally reduced thermal two-phase problems representative for PBF-LB/M in a finite element framework. It is demonstrated that the extreme temperature gradients combined with the high ratios of material properties between metal and ambient gas lead to significant errors in the interface temperatures and fluxes when classical CSF approaches, along with typical interface thicknesses and discretizations, are applied. It is expected that this finding is also relevant for other types of diffuse interface PBF-LB/M melt pool models. A novel parameter-scaled CSF approach is proposed, which is constructed to yield a smoother temperature field in the diffuse interface region, significantly increasing the solution accuracy. The interface thickness required to predict the temperature field with a given level of accuracy is less restrictive by at least one order of magnitude for the proposed parameter-scaled approach compared to classical CSF, drastically reducing computational costs. Finally, we showcase the general applicability of the parameter-scaled CSF to a 3D simulation of stationary laser melting of PBF-LB/M considering the fully coupled thermo-hydrodynamic multi-phase problem, including phase change.

High-speed synchrotron X-ray imaging of melt pool dynamics during ultrasonic melt processing of Al6061

Ultrasonic processing of solidifying metals in additive manufacturing can provide grain refinement and advantageous mechanical properties. However, the specific physical mechanisms of microstructural refinement relevant to laser-based additive manufacturing have not been directly observed because of sub-millimeter length scales and rapid solidification rates associated with melt pools. Here, high-speed synchrotron X-ray imaging is used to observe the effect of ultrasonic vibration directly on melt pool dynamics and solidification of Al6061 alloy. The high temporal and spatial resolution enabled direct observation of cavitation effects driven by a 20.2 kHz ultrasonic source. We utilized multiphysics simulations to validate the postulated connection between ultrasonic treatment and solidification. The X-ray results show a decrease in melt pool and keyhole depth fluctuations during melting and promotion of pore migration toward the melt pool surface with applied sonication. Additionally, the simulation results reveal increased localized melt pool flow velocity, cooling rates, and thermal gradients with applied sonication. This work shows how ultrasonic treatment can impact melt pools and its potential for improving part quality.

Anomalous diffusion of hydrocarbon vapor through an aqueous foam bubble structure

Hydrocarbons are known as “anti-foamers” because they cause bubble rupture, coalescence, and reduce foaming. We show that the dynamics of bubble structure allows hydrocarbon vapors permeate rapidly when an aqueous foam is placed on a hydrocarbon pool. Two distinct foam layers are formed. Vapor accumulates in an expanding bottom layer at the foam-pool interface where bubbles grow rapidly, rupture, and coalesce. Simultaneously, vapor diffuses through a top layer having small bubble structure, which changes slowly due to Ostwald-ripening. Very little vapor accumulates in the top layer, which has a constant thickness equal to the initial foam thickness. Surprisingly, both accumulation in the bottom layer and diffusion through top layer occur at constant rates, which are independent of time and initial foam thickness. The vapor diffusion rate in the top layer should have decreased, inversely proportional to the initial foam thickness, based on classical diffusion theory; only the fluorosurfactant containing foam (RefAFFF) placed on gasoline follows the classical theory where the bottom foam layer is absent. Therefore, we propose a theory to show a linear increase in diffusion time with initial foam thickness using an effective diffusion-coefficient. Experiments show that this variation could be because of increased liquid drainage, drying, and bubble coarsening, which are not considered explicitly in the theory. We also describe a theory for the expanding bottom layer to show that most vapor formed at the pool surface accumulates for very volatile hydrocarbons. The vapor diffusion controls foam ignition. We show that the measured foam ignition time also increases linearly with initial foam thickness, qualitatively consistent with the predicted diffusion time. By employing different hydrocarbons, we show that the measured foam ignition times decrease inversely proportion to square root of hydrocarbon vapor concentration for a given surfactant. This could be because a surfactant exhibits different degrees of oleophobicity towards different hydrocarbons that can reduce vapor adsorption, solubility, and diffusion at a bubble surface. Different surfactants also exhibit different degrees of oleophobicity towards a given hydrocarbon (n-pentane) and increase ignition times by a factor of six: RefAFFF having the longest ignition time, followed by siloxane-polyoxyethylene formulation, and its individual surfactant components.

Structure and Maintenance of a Quasi-Linear Mesoscale Convective System That Caused Torrential Rain in Southern Kyushu, Japan, on 11 July 2021

Abstract A quasi-linear mesoscale convective system that remained nearly stationary (hereafter referred to as a stationary QLCS) for almost 8 h in southern Kyushu, Japan, caused torrential rainfall exceeding 350 mm on 11 July 2021. The stationary QLCS consisted of several rainbands organized by back-building convection. As the cold pool intensified, the system attained a more widespread structure, leaning on the upshear side. To elucidate the mechanism responsible for the upshear tilt, numerical simulations with 250-m horizontal grid spacing were conducted, including sensitivity experiments in which the evaporative cooling rates from rain were reduced to modify the cold pool intensity. Results show that the cold pool is critical to the organization of the QLCS, and the structure normal to it is mainly governed by the balance between the low-level shear magnitude and cold pool intensity, supporting the application of so-called Rotunno–Klemp–Weisman (RKW) theory to this event. The cause of the weak updraft that accompanies the leaning system over the strong cold pool was also investigated, analyzing the trajectories, vertical momentum equation, and pressure perturbation field using the anelastic equation. It is revealed that the updraft travels a longer distance through the tilted system experiencing more mixing with the ambient air, which results in less thermal buoyancy. In addition, the updraft is decelerated by the downward perturbation gradient force owing to the vertical buoyancy gradient around the sloping surface of the cold pool and the dynamical effect caused by the baroclinicity-associated strong horizontal vorticity around the cold pool leading edge.

Plume active control in high-power fiber laser welding based on high-speed shielding gas microbeam

Plume is an inherent physical phenomenon in fiber laser keyhole welding, negatively affecting welding quality. This paper proposes a new type of high-speed shielding gas microbeam (HSGM) based on the limitation of conventional shielding gas regulating plumes. The gas flow characteristics of the HSGM on the molten pool surface were explored using numerical simulation. Then, the coaxial double-layer shielding nozzle was trial-manufactured to clarify the regulation law for the HSGM on the plume. The gas velocity and pressure produced by the HSGM on the molten pool surface were positively correlated with the shielding gas flow rate, and the gas flow pattern was an acute triangle shape. The suitable HSGM can significantly restrain plume formation, improve the weld surface forming quality, increase the weld penetration depth (about 15.4%), and reduce the mass loss of the weld (about 58.7%). The significant blowing pressure effect of HSGM on plumes and splashes was the key to regulating the welding process. Compared with conventional shielding gas, the use of HSGM was significantly reduced.

Nacre-mimetic alternating architecture of Ag[sbnd]SnO2 contact: Highly-efficient synergistic enhancement of in-situ self-repairing erosion resistance and naturally evolving impact resistance

Synergistically enhancing the erosion and impact resistance of contacts poses a significant challenge for cutting-edge electrical equipment. Fortunately, mollusk shells in nature have evolved effective strategies to construct microstructures with superior erosion and impact resistance. Inspired by the structure of nacre, AgSnO2 contact material with hierarchical architectures has been designed and fabricated. The mechanistic link between microstructural evolution and dynamic erosion is studied through experiments combined with Computational Fluid Dynamics (CFD) and Finite Element Method (FEM) simulations. Results show that the reconstructed SnO2 skeleton endowed with a highly continuous and anisotropic ‘flowering'-like structure forms a continuous interpenetrating network with Ag, optimizing the conductive pathways on the molten pool surface. Additionally, the Ag-rich regions in the deeper layers on both sides of the molten pool offers a stable ‘nutrient-supply’ for the continuous ‘flowering’ reconstruction of the skeleton, exhibiting excellent in-situ self-repairing erosion resistance. Benefiting from this synergistic strategy, this skeleton is reconstructed based on its natural structure, which further disperses the stress and deformation concentration while inhibiting interfacial debonding, thereby reducing the formation of cracks and significantly enhancing the impact resistance. This work is expected to breakthrough erosion and impact resistance in extreme condition electrical contact materials through biomimetic microstructure design.

Effect of oxygen in shielding gas on weldability in plasma-GMA hybrid welding process of high-tensile strength steel

This study aims to clarify the effect of oxygen in shielding gas on weldability in the plasma-GMA (Gas Metal Arc) hybrid welding process of high-tensile strength steel plates. The difference in keyhole profile and bead formation, when the GMA shielding gas was pure Ar, Ar + 2% O2, or Ar + 20% CO2, was investigated for plate thicknesses of 6 and 9 mm for the first time. It was found that the weld beads were in good condition for 6 mm thickness plates for all shielding gases, which implied that the window of welding conditions for this thickness is wide. In contrast, for 9 mm thickness plates, a fully penetrated weld bead was achieved only in Ar + 20% CO2, and weld bead penetration in Ar + 20% CO2 is higher than in pure Ar and Ar + 2% O2 in the same welding condition. Due to decreased surface tension caused by sufficiently increased oxygen absorbed into the weld pool, the keyhole diameter increased to penetrate the bottom side of the plate, and the depressing weld pool surface under GMA allowed the heat input from the GMA to be directly applied to a deeper position. Consequently, the plasma-GMA hybrid welding process with Ar + 20% CO2 achieved a complete penetration for a plate of 9 mm thickness, owing to the effects of both phenomena. It proved a potential to increase penetrability in welding thicker plates by controlling oxygen content in shielding gas of GMA adequately.

Bubble ascent and rupture in mud volcanoes.

Large gas bubbles can reach the surface of pools of mud and lava where they burst, often through the formation and expansion of circular holes. Bursting bubbles release volatiles and generate spatter, and hence play a key role in volcanic degassing and volcanic edifice construction. Here, we study the ascent and rupture of bubbles using a combination of field observations at Pâclele Mici (Romania), laboratory experiments with mud from the Imperial Valley (California, USA), numerical simulations and theoretical models. Numerical simulations predict that bubbles ascend through the mud as elliptical caps that develop a dimple at the apex as they impinge on the free surface. We documented the rupture of bubbles in nature and under laboratory conditions using high-speed video. The bursting of mud bubbles starts with the nucleation of multiple holes, which form at a near-constant rate and in quick succession. The quasi-circular holes rapidly grow and coalesce, and the sheet evolves towards a filamentous structure that finally falls back into the mud pool, sometimes breaking up into droplets. The rate of expansion of holes in the sheet can be explained by a generalization of the Taylor-Culick theory, which is shown to hold independent of the fluid rheology.

Mantis shrimp appendages-inspired Ag-CuO contact: Synergistically enhancing the erosion and impact resistance via gradient-layered scatter-island/chain-skeleton structure

Materials degradation induced by repeated arc erosion and impact poses a considerable challenge for Ag-based contacts. Fortunately, nature has evolved efficient strategies to construct complex gradient-layered structure that exhibit exceptional erosion and impact resistance. Drawing inspiration by the mantis shrimp appendages, a chain-like CuO nanofibre-reinforced Ag-CuO contact material with a gradient-layered scatter-island/chain-skeleton structure was designed and fabricated. Employing a combined experimental and simulation approach, the evolution of the microstructure during the erosion process was investigated. Results indicated that the interaction between the mantis shrimp appendage-like structure and the chain-like CuO nanofibres effectively suppressed the formation of cracks and pores on the contact surface. Particularly, the scatter-island layer not only played a crucial role in maintaining the viscosity of the molten pool and establishing stable electrical and thermal pathways, but also functioned as a “supplement” to continuously supply a steady source of Ag onto the molten pool surface, effectively promoting CuO skeleton restructuring. Meanwhile, the CuO skeleton diffusive-continuous restructuring of the chain-skeleton layer restricted molten pool flow, significantly enhancing contact erosion resistance. Furthermore, the strong synergistic effect between the gradient-layered structures dispersed stress and deformation concentration on the contact surface. It effectively delayed the defects formation and suppressed interfacial debonding, thereby endowing the contact with excellent impact resistance. Our work presents a fascinated route for designing novel biomimetic Ag-based contacts.

Dynamics of pore formation and evolution during multi-layer directed energy deposition additive manufacturing via in-situ synchrotron X-ray imaging: A case study on high-entropy Cantor alloy

Blown-powder directed energy deposition (DED) additive manufacturing is impeded for novel alloys processing by perceivable and detrimental porosity. During multi-layer depositions, however, mechanisms of pore formation and evolution remain elusive for developing pore mitigation strategies. Here, conduction-mode multi-layer DED process of an exemplary high-entropy Cantor alloy have been investigated in-situ by high-energy high-speed synchrotron X-ray imaging. Three new pore formation mechanisms are unveiled when depositing first layer and successive layers: gas pore induced by high-velocity powder injection into melt pool, pore generated from swirl shear of turbulent melt flow, and pore trapped by surface wave. Three pore formation mechanisms are reconfirmed: pore inheritance from feedstock powder, pore generation when laser remelting defect-sensitive locations of existing pore from previous layer or unmelted powder attached on the melt pool surface, and pore formation as cooling of melt pool. A unique mechanism for pore elimination is proposed: a counter-Marangoni melt flow is experimentally found in the stable melt pool and contributes to the prolonged pore lifetime at tens of milliseconds scale; pores are prone to coalesce into larger sizes in laser interaction zone and the adjacent location with circulation zone; coalesced larger pores driven by combined effect of Marangoni and buoyant forces easily get eliminated from melt pool. The results of pore formation and evolution dynamics revealed in Cantor alloy provide quantified experimental data for high-fidelity computational modeling and in-depth insights of porosity control for high-entropy alloy printing down to melt pool scale.

Interface characteristics of selective laser melted stainless steel 316L and Inconel 718

Additive manufactured dissimilar metal constructs of alternating Inconel 718 and Stainless Steel 316L layers were fabricated by using selective laser melting. The solidified interfaces between two materials were examined to understand the interface characteristics. No distinct horizontal layers have been observed and undulating dissimilar interfaces at meso-scale. The undulations of the interfacing are understood a result of the melt pool surface oscillations driven by forces such as surface tension. The shape of the interface and the chemical distribution across the interface implied that the mass transport by the flow can significantly influence the interface morphology.