Journal articles: 'Laser directed energy deposition'

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Lia, Frederick, Joshua Park, Jay Tressler, and Richard Martukanitz. "Partitioning of laser energy during directed energy deposition." Additive Manufacturing 18 (December 2017): 31–39. http://dx.doi.org/10.1016/j.addma.2017.08.012.

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Hauser, Tobias, Raven T. Reisch, Tobias Kamps, Alexander F. H. Kaplan, and Joerg Volpp. "Acoustic emissions in directed energy deposition processes." International Journal of Advanced Manufacturing Technology 119, no. 5-6 (January 7, 2022): 3517–32. http://dx.doi.org/10.1007/s00170-021-08598-8.

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AbstractAcoustic emissions in directed energy deposition processes such as wire arc additive manufacturing and directed energy deposition with laser beam/metal are investigated within this work, as many insights about the process can be gained from this. In both processes, experienced operators can hear whether a process is running stable or not. Therefore, different experiments for stable and unstable processes with common process anomalies were carried out, and the acoustic emissions as well as process camera images were captured. Thereby, it was found that stable processes show a consistent mean intensity in the acoustic emissions for both processes. For wire arc additive manufacturing, it was found that by the Mel spectrum, a specific spectrum adapted to human hearing, the occurrence of different process anomalies can be detected. The main acoustic source in wire arc additive manufacturing is the plasma expansion of the arc. The acoustic emissions and the occurring process anomalies are mainly correlating with the size of the arc because that is essentially the ionized volume leading to the air pressure which causes the acoustic emissions. For directed energy deposition with laser beam/metal, it was found that by the Mel spectrum, the occurrence of an unstable process can also be detected. The main acoustic emissions are created by the interaction between the powder and the laser beam because the powder particles create an air pressure through the expansion of the particles from the solid state to the liquid state when these particles are melted. These findings can be used to achieve an in situ quality assurance by an in-process analysis of the acoustic emissions.

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Jardon, Zoé, Julien Ertveldt, Raphaël Lecluyse, Michaël Hinderdael, and Lincy Pyl. "Directed Energy Deposition roughness mitigation through laser remelting." Procedia CIRP 111 (2022): 180–84. http://dx.doi.org/10.1016/j.procir.2022.08.042.

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Chen, Yitao, Xinchang Zhang, Mohammad Masud Parvez, and Frank Liou. "A Review on Metallic Alloys Fabrication Using Elemental Powder Blends by Laser Powder Directed Energy Deposition Process." Materials 13, no. 16 (August 12, 2020): 3562. http://dx.doi.org/10.3390/ma13163562.

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The laser powder directed energy deposition process is a metal additive manufacturing technique, which can fabricate metal parts with high geometric and material flexibility. The unique feature of in-situ powder feeding makes it possible to customize the elemental composition using elemental powder mixture during the fabrication process. Thus, it can be potentially applied to synthesize industrial alloys with low cost, modify alloys with different powder mixtures, and design novel alloys with location-dependent properties using elemental powder blends as feedstocks. This paper provides an overview of using a laser powder directed energy deposition method to fabricate various types of alloys by feeding elemental powder blends. At first, the advantage of laser powder directed energy deposition in manufacturing metal alloys is described in detail. Then, the state-of-the-art research and development in alloys fabricated by laser powder directed energy deposition through a mix of elemental powders in multiple categories is reviewed. Finally, critical technical challenges, mainly in composition control are discussed for future development.

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Wang, Hao, Weiwei Liu, Zijue Tang, Yiwen Wang, Xiaolei Mei, Kazi M. Saleheen, Zhenqiu Wang, and Hongchao Zhang. "Review on adaptive control of laser-directed energy deposition." Optical Engineering 59, no. 07 (July 6, 2020): 1. http://dx.doi.org/10.1117/1.oe.59.7.070901.

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Ascari, Alessandro, Adrian H. A. Lutey, Erica Liverani, and Alessandro Fortunato. "Laser Directed Energy Deposition of Bulk 316L Stainless Steel." Lasers in Manufacturing and Materials Processing 7, no. 4 (September 12, 2020): 426–48. http://dx.doi.org/10.1007/s40516-020-00128-w.

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Liu, Xiao, Haoren Wang, Kevin Kaufmann, and Kenneth Vecchio. "Directed energy deposition of pure copper using blue laser." Journal of Manufacturing Processes 85 (January 2023): 314–22. http://dx.doi.org/10.1016/j.jmapro.2022.11.064.

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Wang, Qian, Jianyi Li, Abdalla R. Nassar, Edward W. Reutzel, and Wesley F. Mitchell. "Model-Based Feedforward Control of Part Height in Directed Energy Deposition." Materials 14, no. 2 (January 11, 2021): 337. http://dx.doi.org/10.3390/ma14020337.

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Control of the geometric accuracy of a metal deposit is critical in the repair and fabrication of complex components through Directed Energy Deposition (DED). This paper developed and experimentally evaluated a model-based feedforward control of laser power with the objective of achieving the targeted part height in DED. Specifically, based on the dynamic model of melt-pool geometry derived from our prior work, a nonlinear inverse-dynamics controller was derived in a hatch-by-hatch, layer-by-layer manner to modulate the laser power such that the melt-pool height was regulated during the simulated build process. Then, the laser power trajectory from the simulated closed-loop control under the nonlinear inverse-dynamics controller was implemented as a feedforward control in an Optomec Laser-Engineered Net Shape (LENS) MR-7 system. This paper considered the deposition of L-shaped structures of Ti-6AL-4V as a case study to illustrate the proposed model-based controller. Experimental validation showed that by applying the proposed model-based feed-forward control for laser power, the resulting build had 24–42% reduction in the average build height error with respect to the target build height compared to applying a constant laser power through the entire build or applying a hatch-dependent laser power strategy, for which the laser power values were obtained from experimental trial and error.

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Wang, Qian, Jianyi Li, Abdalla R. Nassar, Edward W. Reutzel, and Wesley F. Mitchell. "Model-Based Feedforward Control of Part Height in Directed Energy Deposition." Materials 14, no. 2 (January 11, 2021): 337. http://dx.doi.org/10.3390/ma14020337.

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Control of the geometric accuracy of a metal deposit is critical in the repair and fabrication of complex components through Directed Energy Deposition (DED). This paper developed and experimentally evaluated a model-based feedforward control of laser power with the objective of achieving the targeted part height in DED. Specifically, based on the dynamic model of melt-pool geometry derived from our prior work, a nonlinear inverse-dynamics controller was derived in a hatch-by-hatch, layer-by-layer manner to modulate the laser power such that the melt-pool height was regulated during the simulated build process. Then, the laser power trajectory from the simulated closed-loop control under the nonlinear inverse-dynamics controller was implemented as a feedforward control in an Optomec Laser-Engineered Net Shape (LENS) MR-7 system. This paper considered the deposition of L-shaped structures of Ti-6AL-4V as a case study to illustrate the proposed model-based controller. Experimental validation showed that by applying the proposed model-based feed-forward control for laser power, the resulting build had 24–42% reduction in the average build height error with respect to the target build height compared to applying a constant laser power through the entire build or applying a hatch-dependent laser power strategy, for which the laser power values were obtained from experimental trial and error.

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Kim, Kang-Hyung, Chan-Hyun Jung, Dae-Yong Jeong, and Soong-Keun Hyun. "Causes and Measures of Fume in Directed Energy Deposition: A Review." Korean Journal of Metals and Materials 58, no. 6 (June 5, 2020): 383–96. http://dx.doi.org/10.3365/kjmm.2020.58.6.383.

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Pores and cracks are known as the main defects in metal additive manufacturing (MAM), including directed energy deposition(DED). A gaseous fume is often produced by laser flash (instantaneous high temperature) during laser processing, which may cause various defects such as porosity, lack of fusion, inhomogeneity, low flowability and composition change, either. However the cause and harmful effects of fume generation in DED are known little. In laser processing, especially laser welding, many studies have been conducted on the prevention of fume because it generates defects that hinder uniform reactions between the laser beam and the materials. Generally, the fume occurs with easily vaporizing low melting point components or sensitive oxidizing elements. Unsuitable conditions are also known to have an effect, including laser power, travel speed, powder feed rate and shielding gas supply. Practically, there are many more fume generating factors in the DED process, and the lack of understanding requires a lot of trial and error. In this article the laser-related and weld metallurgy literatures were reviewed, focusing on the prevention of fume in powder DED. The causes of the fume, were explained to result from the stages of cavitation bubbles generated by the laser induced plasma and the nanoparticles released. Additionally, the effects of alloying components and environmental conditions for fume generation in the DED process were investigated, and suggestions are proposed to prevent fume.

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11

Doux, Adrien, and Vincent Philippe. "Thermomechanical modeling of IN718 alloy directed energy deposition process." MATEC Web of Conferences 304 (2019): 01023. http://dx.doi.org/10.1051/matecconf/201930401023.

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Directed Energy Deposition (DED) Additive Manufacturing (AM) processes have a great potential to be used as cost-effective and efficient repairing and re-manufacturing processes for aerospace components such as turbine blades and landing gears. The AMOS project intends to connect repair and re-manufacturing strategies with design through accurate DED process simulation and novel multi-disciplinary design optimisation (MDO) methods. The ultimate goal is to reduce aerospace component weaknesses at design stage and prolong their lifecycles. DED AM processes are multi-physical phenomena involving high laser power melting powder or wire on a substrate. An experimental heat source has been calibrated using a heat transfer analysis of IN718 laser and powder AM on a sample part. Residual stresses and final distortion are also computed using thermal field and the evolving part distortion at each increment. Multiple hypotheses have been considered model the molten pool creation on the Heat Affected Zone (HAZ).

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Jinoop, AN, CP Paul, and KS Bindra. "Laser-assisted directed energy deposition of nickel super alloys: A review." Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 233, no. 11 (May 27, 2019): 2376–400. http://dx.doi.org/10.1177/1464420719852658.

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Laser additive manufacturing using directed energy deposition (LAM-DED) is an advanced manufacturing process widely deployed for fabricating near net-shaped engineering components. LAM-DED has been successfully used for processing wide variety of pure metals and their alloys. The list of these metals and alloys is appending rapidly. Among the various materials successfully deployed for LAM-DED, nickel super alloys are extensively used for various engineering applications due to the unique combination of superior properties, such as high temperature strength, oxidation, corrosion resistance, etc. Recent studies show that LAM-DED built nickel super alloys finds wide applications in aerospace and automotive sector for fabricating engineering components, repairing, remanufacturing, and cladding. Considering the importance of LAM-DED and nickel super alloys, significant amount of work is already reported. This paper presents a comprehensive review on LAM-DED of nickel super alloys. It introduces LAM technology and nickel super alloys with a compilation of various lasers and processing parameters deployed for LAM-DED of nickel super alloys. The paper compiles the metallurgy, mechanical properties, processing issues, and effect of post-processing on LAM-DED built nickel super alloys. This paper will serve as a quick-start for novices to understand LAM-DED of nickel super alloys and will be useful as a reference document for researchers and industrialists in the field.

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Svetlizky, David, Baolong Zheng, Alexandra Vyatskikh, Mitun Das, Susmita Bose, Amit Bandyopadhyay, Julie M. Schoenung, Enrique J. Lavernia, and Noam Eliaz. "Laser-based directed energy deposition (DED-LB) of advanced materials." Materials Science and Engineering: A 840 (April 2022): 142967. http://dx.doi.org/10.1016/j.msea.2022.142967.

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14

Piscopo, Gabriele, Eleonora Atzeni, Alessandro Salmi, Luca Iuliano, Andrea Gatto, Giovanni Marchiandi, and Andrea Balestrucci. "Mesoscale modelling of laser powder-based directed energy deposition process." Procedia CIRP 88 (2020): 393–98. http://dx.doi.org/10.1016/j.procir.2020.05.068.

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15

Pirch, N., S. Linnenbrink, A. Gasser, and H. Schleifenbaum. "Laser-aided directed energy deposition of metal powder along edges." International Journal of Heat and Mass Transfer 143 (November 2019): 118464. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2019.118464.

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16

Knapp, Cameron Myron, Thomas J. Lienert, Paul Burgardt, Patrick Wayne Hochanadel, and Desiderio Kovar. "A model to predict deposition parameters for directed energy deposition: part I theory and modeling." Rapid Prototyping Journal 25, no. 6 (July 8, 2019): 998–1006. http://dx.doi.org/10.1108/rpj-08-2018-0221.

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Purpose Directed energy deposition (DED) with laser powder-feed is an additive manufacturing process that is used to produce metallic components by simultaneously providing a supply of energy from a laser and mass from a powder aerosol. The breadth of alloys used in DED is currently limited to a very small range as compared to wrought or cast alloys. The purpose of this paper is to develop the new alloys for DED is limited because current models to predict operational processing parameters are computationally expensive and trial-and-error based experiments are both expensive and time-consuming. Design/methodology/approach In this research, an agile DED model is presented to predict the geometry produced by a single layer deposit. Findings The utility of the model is demonstrated for type 304 L stainless steel and the significance of the predicted deposition regimes is discussed. The proposed model incorporates concepts from heat transfer, welding and laser cladding; and integrates them with experimental fits and physical models that are relevant to DED. Originality/value The utility of the model is demonstrated for type 304 L stainless steel and the significance of the predicted deposition regimes is discussed.

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Sciammarella, Federico, and Benyamin Salehi Najafabadi. "Processing Parameter DOE for 316L Using Directed Energy Deposition." Journal of Manufacturing and Materials Processing 2, no. 3 (September 7, 2018): 61. http://dx.doi.org/10.3390/jmmp2030061.

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The ability to produce consistent material properties across a single or series of platforms, particularly over time, is the major objective in metal additive manufacturing (MAM) research. If this can be achieved, it will result in widespread adoption of the technology for industry and place it into mainstream manufacturing. However, before this can happen, it is critical to develop an understanding of how processing parameters influence the thermal conditions which dictate the mechanical properties of MAM builds. Research work reported in the literature of MAM is generally based on a set of parameters and/or the review of a few parameter changes, and observing the effects that these changes (i.e., microstructure, mechanical properties) have. While these articles provide results with some insight, there lacks a standard approach that can be used to allow meaningful comparisons and conclusions to be made concerning the optimization of the processing variables. This study provides a template which can be used for making comparisons across DED platforms. The tests are performed with a design of experiments (DOE) philosophy directed to evaluate the effect of selected parameters on the measured properties of the DED builds. Specifically, a laser engineering net shaping system (LENS) is used to build multilayered 316L coupons and analyze how build parameters such as laser power, travel speed, and powder feed rate influence the thermal conditions that will define both microstructure and microhardness. A fundamental conclusion of this research is that it is possible to repeatedly obtain a consistent microstructure that contains a fine cellular substructure with a low level of porosity (less than 1.1%) and with microhardness that is equal to or better than wrought 316L. This is mainly achieved by maintaining an associated powder flow to travel speed ratio at the power level, ensuring an appropriate net heat input for the build process.

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Schaible, Jonathan, David Hausch, Thomas Schopphoven, and Constantin Häfner. "Deposition strategies for generating cuboid volumes using extreme high-speed directed energy deposition." Journal of Laser Applications 34, no. 4 (November 2022): 042034. http://dx.doi.org/10.2351/7.0000770.

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Extreme high-speed directed energy deposition (EHLA) is a variant of directed energy deposition (DED-LB) developed at Fraunhofer ILT in cooperation with RWTH Aachen University. Because of a powder gas jet setup that is aimed at melting particles in the laser beam before they enter the melting pool, high process speeds of up to several hundred meters per minute and a layer thickness as thin as 25 μm can be achieved. EHLA is generally applied for rotationally symmetric coating applications. In previous experiments on a prototype machine of ponticon GmbH, EHLA was used for building up dense volumes, thus qualifying its use for additive manufacturing, now termed EHLA 3D. In this work, using iron-base alloy 1.4404 and a process speed of 40 m/min, cubic volumes are produced with EHLA 3D. Different deposition strategies commonly used in DED-LB are tested for their transferability to EHLA 3D. The results of different deposition strategies achieving the best near net shape geometry are shown in comparison to DED-LB. Furthermore, the influence of the deposition strategy and used technology on thermal management and microstructure are investigated. The best near net shape is achieved in this comparison using a contour-hatch strategy with 1.5 contours per layer and a 90° rotation of the hatch, both for EHLA and DED-LB. The microstructure of EHLA 3D built cubes is more similar to a typical laser powder bed fusion microstructure than to a typical DED-LB microstructure with respect to grain size and structure.

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Kim, Kang-Hyung, Chan-Hyun Jung, Dae-Yong Jeong, and Soong-Keun Hyun. "Preventing Evaporation Products for High-Quality Metal Film in Directed Energy Deposition: A Review." Metals 11, no. 2 (February 19, 2021): 353. http://dx.doi.org/10.3390/met11020353.

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Directed energy deposition (DED), a type of additive manufacturing (AM) is a process that enables high-speed deposition using laser technology. The application of DED extends not only to 3D printing, but also to the 2D surface modification by direct laser-deposition dissimilar materials with a sub-millimeter thickness. One of the reasons why DED has not been widely applied in the industry is the low velocity with a few m/min, but thin-DED has been developed to the extent that it can be over 100 m/min in roller deposition. The remaining task is to improve quality by reducing defects. Thus far, defect studies on AM, including DED, have focused mostly on preventing pores and crack defects that reduce fatigue strength. However, evaporation products, fumes, and spatters, were often neglected despite being one of the main causes of porosity and defects. In high-quality metal deposition, the problems caused by evaporation products are difficult to solve, but they have not yet caught the attention of metallurgists and physicists. This review examines the effect of the laser, material, and process parameters on the evaporation products to help obtain a high-quality metal film layer in thin-DED.

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Borovkov, Herman, Aitor Garcia de la Yedra, Xabier Zurutuza, Xabier Angulo, Pedro Alvarez, Juan Carlos Pereira, and Fernando Cortes. "In-Line Height Measurement Technique for Directed Energy Deposition Processes." Journal of Manufacturing and Materials Processing 5, no. 3 (August 5, 2021): 85. http://dx.doi.org/10.3390/jmmp5030085.

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Directed energy deposition (DED) is a family of additive manufacturing technologies. With these processes, metal parts are built layer by layer, introducing dynamics that propagate in time and layer-domains, which implies additional complexity and consequently, the resulting part quality is hard to predict. Control of the deposit layer thickness and height is a critical issue since it impacts on geometrical accuracy, process stability, and the overall quality of the product. Therefore, online feedback height control for DED processes with proper sensor strategies is required. This work presents a novel vision-based triangulation technique through an off-axis located CCD camera synchronized with a 640 nm wavelength pulsed illumination laser. Image processing and machine vision techniques allow in-line height measurement right after metal solidification. The linearity and the precision of the proposed setup are validated through off-and in-process trials in the laser metal deposition (LMD) process. Besides, the performance of the developed in-line inspection system has also been tested for the Arc based DED process and compared against experimental weld bead characterization data. In this last case, the system additionally allowed for the measurement of weld bead width and contact angles, which are critical in first runs of multilayer buildups.

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Naesstroem, Himani, Frank Brueckner, and Alexander F. H. Kaplan. "From mine to part: directed energy deposition of iron ore." Rapid Prototyping Journal 27, no. 11 (July 19, 2021): 37–42. http://dx.doi.org/10.1108/rpj-10-2020-0243.

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Purpose This paper aims to gain an understanding of the behaviour of iron ore when melted by a laser beam in a continuous manner. This fundamental knowledge is essential to further develop additive manufacturing routes such as production of low cost parts and in-situ reduction of the ore during processing. Design/methodology/approach Blown powder directed energy deposition was used as the processing method. The process was observed through high-speed imaging, and computed tomography was used to analyse the specimens. Findings The experimental trials give preliminary results showing potential for the processability of iron ore for additive manufacturing. A large and stable melt pool is formed in spite of the inhomogeneous material used. Single and multilayer tracks could be deposited. Although smooth and even on the surface, the single layer tracks displayed porosity. In case of multilayered tracks, delamination from the substrate material and deformation can be seen. High-speed videos of the process reveal various process phenomena such as melting of ore powder during feeding, cloud formation, melt pool size, melt flow and spatter formation. Originality/value Very little literature is available that studies the possible use of ore in additive manufacturing. Although the process studied here is not industrially useable as is, it is a step towards processing cheap unprocessed material with a laser beam.

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Kisielewicz, Agnieszka, Karthikeyan Thalavai Pandian, Daniel Sthen, Petter Hagqvist, Maria Asuncion Valiente Bermejo, Fredrik Sikström, and Antonio Ancona. "Hot-Wire Laser-Directed Energy Deposition: Process Characteristics and Benefits of Resistive Pre-Heating of the Feedstock Wire." Metals 11, no. 4 (April 13, 2021): 634. http://dx.doi.org/10.3390/met11040634.

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This study investigates the influence of resistive pre-heating of the feedstock wire (here called hot-wire) on the stability of laser-directed energy deposition of Duplex stainless steel. Data acquired online during depositions as well as metallographic investigations revealed the process characteristic and its stability window. The online data, such as electrical signals in the pre-heating circuit and images captured from side-view of the process interaction zone gave insight on the metal transfer between the molten wire and the melt pool. The results show that the characteristics of the process, like laser-wire and wire-melt pool interaction, vary depending on the level of the wire pre-heating. In addition, application of two independent energy sources, laser beam and electrical power, allows fine-tuning of the heat input and increases penetration depth, with little influence on the height and width of the beads. This allows for better process stability as well as elimination of lack of fusion defects. Electrical signals measured in the hot-wire circuit indicate the process stability such that the resistive pre-heating can be used for in-process monitoring. The conclusion is that the resistive pre-heating gives additional means for controlling the stability and the heat input of the laser-directed energy deposition.

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Piscopo, Gabriele, and Luca Iuliano. "Current research and industrial application of laser powder directed energy deposition." International Journal of Advanced Manufacturing Technology 119, no. 11-12 (January 26, 2022): 6893–917. http://dx.doi.org/10.1007/s00170-021-08596-w.

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AbstractAdditive Manufacturing (AM) technologies are recognized as the future of the manufacturing industry thanks to their possibilities in terms of shape design, part functionality, and material efficiency. The use of AM technologies in many industrial sectors is growing, also due to the increasing knowledge regarding the AM processes and the characteristics of the final part. One of the most promising AM techniques is the Directed Energy Deposition (DED) that uses a thermal source to generate a melt pool on a substrate into which metal powder is injected. The potentialities of DED technology are the ability to process large build volumes (> 1000 mm in size), the ability to deliver the material directly into the melt pool, the possibility to repair existing parts, and the opportunity to change the material during the building process, thus creating functionally graded material. In this paper, a review of the industrial applications of Laser Powder Directed Energy Deposition (LP-DED) is presented. Three main applications are identified in repairing, designed material, and production. Despite the enormous advantages of LP-DED, from the literature, it emerges that the most relevant application refers to the repairing process of high-value components.

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Huanes-Alvan, Guillermo E., Beytullah Aydogan, Himanshu Sahasrabudhe, and Sunil Kishore Chakrapani. "Ultrasonic properties of Inconel 718 fabricated via laser-directed energy deposition." Journal of the Acoustical Society of America 148, no. 4 (October 2020): 2648. http://dx.doi.org/10.1121/1.5147361.

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Haley, James C., Baolong Zheng, Umberto Scipioni Bertoli, Alexander D. Dupuy, Julie M. Schoenung, and Enrique J. Lavernia. "Working distance passive stability in laser directed energy deposition additive manufacturing." Materials & Design 161 (January 2019): 86–94. http://dx.doi.org/10.1016/j.matdes.2018.11.021.

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Piscopo, Gabriele, Eleonora Atzeni, Abdollah Saboori, and Alessandro Salmi. "An Overview of the Process Mechanisms in the Laser Powder Directed Energy Deposition." Applied Sciences 13, no. 1 (December 22, 2022): 117. http://dx.doi.org/10.3390/app13010117.

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Laser Powder Directed Energy Deposition (LP-DED) is a very powerful Additive Manufacturing process for different applications, such as repair operations and the production of functionally graded material. However, the application is still limited, and one of the main reasons is related to the lack of knowledge of the process mechanisms. Since the mechanisms involved in the process, which are mutually related to each other, directly influence the properties of the produced part, their knowledge is crucial. This paper presents a review of the LP-DED mechanisms and the relationship between the input process parameters and related outcomes. The main mechanisms of the LP-DED process, which are identified as (i) laser irradiation and material addition, (ii) melt pool generation, and (iii) subsequent solidification, are discussed in terms of input parameters, with a focus on their effects on the deposition effectiveness, and interrelation among the mechanisms of the deposition process. The results highlight the complexity of the mechanisms involved in the LP-DED process and guide engineers in navigating the challenges of the deposition process, with a specific focus on the critical parameters that should be investigated when new materials are developed, or process optimization is carried out.

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Hu, Ankai, Yanlu Huang, Yu Wang, Yongqiang Yang, Wei Li, and Tianyu Wang. "Numerical Simulation and Experimental Research on Multi-Channel Laser Directional Energy Deposition of IN718." Applied Sciences 12, no. 21 (October 31, 2022): 11014. http://dx.doi.org/10.3390/app122111014.

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In this paper, the deposition layer calculation model is proposed for laser-directed energy deposition (DED) with coaxial powder feeding by combining the powder feeding equation with the volume of fluid (VOF) method, and the single-channel IN718 forming process is simulated in real-time with moving boundary conditions in a fixed coordinate system and experimentally validated. Under single-layer single-channel deposition processing, the deposition height and width decreased by 57.1% and 21.6%, respectively, as the scanning speed increased from 8 mm/s to 14 mm/s. The calculated deposition height, width, and melt pool depth were in good agreement with the experimental results. Calculating the temperature field distribution of the single-layer double-channel deposition at an overlapping-rate of 30% yielded the temperature fluctuation pattern of the deposition at various lap moments. Under the influence of the thermal accumulation of the first deposition channel, the latent heat effect of the melt pool will cause the maximum surface temperature during overlap processing to be slightly lower than the maximum surface temperature during single channel processing; at the same time, under the influence of the high-temperature state of the overlap deposition channel during the scanning process, the first deposition channel will exhibit rewarming during the overlap scanning process. The deposition layer and temperature field of single-layer multi-channel laser deposition are modelled using this information. It has been proved that the model may be used to forecast deposition and temperature fields for intricate processing procedures. The study findings are significant for understanding the process mechanism of coaxial powder feeding laser-directed energy deposition in detail and optimizing the process.

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Chen, Yitao, Cesar Ortiz Rios, Braden McLain, Joseph W. Newkirk, and Frank Liou. "TiNi-Based Bi-Metallic Shape-Memory Alloy by Laser-Directed Energy Deposition." Materials 15, no. 11 (June 1, 2022): 3945. http://dx.doi.org/10.3390/ma15113945.

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In this study, laser-directed energy deposition was applied to build a Ti-rich ternary Ti–Ni–Cu shape-memory alloy onto a TiNi shape-memory alloy substrate to realize the joining of the multifunctional bi-metallic shape-memory alloy structure. The cost-effective Ti, Ni, and Cu elemental powder blend was used for raw materials. Various material characterization approaches were applied to reveal different material properties in two sections. The as-fabricated Ti–Ni–Cu alloy microstructure has the TiNi phase as the matrix with Ti2Ni secondary precipitates. The hardness shows no high values indicating that the major phase is not hard intermetallics. A bonding strength of 569.1 MPa was obtained by tensile testing, and digital image correlation reveals the different tensile responses of the two sections. Differential scanning calorimetry was used to measure the phase-transformation temperatures. The austenite finishing temperature of higher than 80 °C was measured for the Ti–Ni–Cu alloy section. For the TiNi substrate, the austenite finishing temperature was tested to be near 47 °C at the bottom and around 22 °C at the upper substrate region, which is due to the repeated laser scanning that acts as annealing on the substrate. Finally, the multiple shape-memory effect of two shape-memory alloy sides was tested and identified.

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Metel, Alexander S., Tatiana Tarasova, Andrey Skorobogatov, Pavel Podrabinnik, Yury Melnik, and Sergey N. Grigoriev. "Feasibility of Production of Multimaterial Metal Objects by Laser-Directed Energy Deposition." Metals 12, no. 10 (September 21, 2022): 1566. http://dx.doi.org/10.3390/met12101566.

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The article focuses on the possibility of manufacturing bimetallic products for specific industrial applications using laser-directed energy deposition (LDED) additive technology to replace the traditional brazing process. Preferential process regimes were determined by parametric analysis for the nickel-alloy–steel and molybdenum–steel pairs. Comparative studies of the microstructure and hardness of the deposited layers and the transition layer at the boundary of the alloyed materials have been carried out. It is shown that LDED provides better transition layer and operational properties of the final part since the low-melting copper layer is no longer needed. A combined technological process has been developed, which consists in combining the traditional method of manufacturing a workpiece through the casting and deposition of a molybdenum layer by LDED.

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Urresti Ubillos, Aizpea, JON IÑAKI ARRIZUBIETA ARRATE, Oihane Murua De la Mata, Miren Aristizabal, ENEKO UKAR ARRIEN, and DAVID LOPEZ BOLAÑOS. "VIABILITY ANALISYS FOR LASER DIRECTED ENERGY DEPOSITION (L-DED) OF POWDER MATERIAL15CDV6." DYNA 98, no. 1 (January 1, 2023): 45–50. http://dx.doi.org/10.6036/10657.

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The aim of the present research work is the characterization of the 15CDV6 powder material for Laser Directed Energy Deposition (L DED) processes. The novelty of the work lays on the fact that this aeronautical steel has never been employed before in powder L DED process. Therefore, the mentioned steel powder was atomized specifically for the present work and the chemical composition and shape of the particles was measured to ensure the quality of the material. Afterwards, the suitability of the 15CDV6 steel for the L-DED process was studied and the employed methodology consisted of 3 sequential steps: single bead tests, overlapping beads deposition and thin wall construction. The results of each sequence are used as the basis for the following ones. In addition to the determination of the main process parameters, the influence of the deposition strategy on the process efficiency is analyzed and a correlation between the microstructure resulting from the thermal process and the hardness HV0.3 values was obtained. To finish the characterization of the process, a demonstrator part was fabricated using the optimum parameters defined during the tests. Based on the obtained results, the viability of employing 15CDV6 steel in the L-DED process is ensured. Also, it is concluded that if a sufficient cooling rate is ensured, Acicular Ferrite microstructure is obtained, which provides good mechanical properties to the L-DED manufactured parts. Nevertheless, the thermal evolution of the process needs to be controlled in order to avoid heat accumulation and cooling stops are to be applied when required. Keywords: 15CDV6, powder, L-DED, characterization, atomization.

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Barragan, German, Fabio Mariani, and Reginaldo Coelho. "Ti6Al4V Thin Walls Production using Laser Directed Energy Deposition (L-DED) Process." International Journal of Engineering Materials and Manufacture 6, no. 3 (July 15, 2021): 124–31. http://dx.doi.org/10.26776/ijemm.06.03.2021.03.

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One of the main applications of Directed Energy Deposition (DED) is the production of thin-wall structures, where it has significant advantages over traditional milling and machining techniques, or even welded analogues. These kinds of structures are frequently employed in aerospace components, field where titanium alloys have a primary role to play. Amongst them, the most employed is the Ti6Al4V with an alpha + beta alloy containing 6% Aluminium (Al) and 4% Vanadium (V). It has an excellent combination of strength and toughness along with excellent corrosion resistance. For the study hereby, thin-wall structures were constructed employing a Laser Directed Energy Deposition machine (L-DED), working with powder material. Analyse identified some microstructural and mechanical characteristics, thorough metallographic study, wear test (micro-adhesive) and micro hardness test. Finding a grain refined structure with competitive mechanical properties compared to materials manufactured by traditional processes. Results positioning DED as an attractive manufacturing technology, with a huge potential to improve costs and material usage, besides almost no restriction on component shape.

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dos Santos Paes, Luiz Eduardo, Henrique Santos Ferreira, Milton Pereira, Fábio Antônio Xavier, Walter Lindolfo Weingaertner, and Louriel Oliveira Vilarinho. "Modeling layer geometry in directed energy deposition with laser for additive manufacturing." Surface and Coatings Technology 409 (March 2021): 126897. http://dx.doi.org/10.1016/j.surfcoat.2021.126897.

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Paul, A. C., A. N. Jinoop, C. P. Paul, P. Deogiri, and K. S. Bindra. "Investigating build geometry characteristics during laser directed energy deposition based additive manufacturing." Journal of Laser Applications 32, no. 4 (November 2020): 042002. http://dx.doi.org/10.2351/7.0000004.

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Dass, Adrita, Ashlee Gabourel, Darren Pagan, and Atieh Moridi. "Laser based directed energy deposition system for operando synchrotron x-ray experiments." Review of Scientific Instruments 93, no. 7 (July 1, 2022): 075106. http://dx.doi.org/10.1063/5.0081186.

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The adoption of metal additive manufacturing (AM) has tremendously increased over the years; however, it is still challenging to explain the fundamental physical phenomena occurring during these stochastic processes. To tackle this problem, we have constructed a custom metal AM system to simulate powder fed directed energy deposition. This instrument is integrated at the Cornell High Energy Synchrotron Source to conduct operando studies of the metal AM process. These operando experiments provide valuable data that can be used for various applications, such as (a) to study the response of the material to non-equilibrium solidification and intrinsic heat treatment and (b) to characterize changes in lattice plane spacing, which helps us calculate the thermo-mechanical history and resulting microstructural features. Such high-fidelity data are made possible by state-of-the-art direct-detection x-ray area detectors, which aid in the observation of solidification pathways of different metallic alloys. Furthermore, we discuss the various possibilities of analyzing the synchrotron dataset with examples across different measurement modes.

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Jamieson, Cory D., Marissa C. Brennan, Todd J. Spurgeon, Stephen W. Brown, Jayme S. Keist, and Edward W. Reutzel. "Tailoring alloy 718 laser directed energy deposition process strategies for repair applications." Journal of Laser Applications 34, no. 1 (February 2022): 012018. http://dx.doi.org/10.2351/7.0000534.

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Vundru, Chaitanya, Ramesh Singh, Wenyi Yan, and Shyamprasad Karagadde. "Non-dimensional process maps for residual stress in laser directed energy deposition." Procedia Manufacturing 48 (2020): 697–705. http://dx.doi.org/10.1016/j.promfg.2020.05.102.

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Kisielewicz, Agnieszka, Fredrik Sikström, Anna-Karin Christiansson, and Antonio Ancona. "Spectroscopic monitoring of laser blown powder directed energy deposition of Alloy 718." Procedia Manufacturing 25 (2018): 418–25. http://dx.doi.org/10.1016/j.promfg.2018.06.112.

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Kumara, Chamara, Andreas Segerstark, Fabian Hanning, Nikhil Dixit, Shrikant Joshi, Johan Moverare, and Per Nylén. "Microstructure modelling of laser metal powder directed energy deposition of alloy 718." Additive Manufacturing 25 (January 2019): 357–64. http://dx.doi.org/10.1016/j.addma.2018.11.024.

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Naiel, Mohamed A., Deniz Sera Ertay, Mihaela Vlasea, and Paul Fieguth. "Adaptive vision-based detection of laser-material interaction for directed energy deposition." Additive Manufacturing 36 (December 2020): 101468. http://dx.doi.org/10.1016/j.addma.2020.101468.

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Benarji, K., Y. Ravi Kumar, CP Paul, AN Jinoop, and KS Bindra. "Parametric investigation and characterization on SS316 built by laser-assisted directed energy deposition." Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 234, no. 3 (December 15, 2019): 452–66. http://dx.doi.org/10.1177/1464420719894718.

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In the present work, parametric investigation and characterization of stainless steel 316 (SS316) built by laser-assisted directed energy deposition (L-DED) is performed. Single-track L-DED experiments are carried by varying laser power, scanning speed, and powder feed rate using full factorial experimental design. The effect of L-DED process parameters on the track geometry, deposition rate, and microhardness is investigated, and three different combinations of process parameters yielding maximum deposition rate and hardness are identified for bulk investigation. The identified process parameters are laser power of 1000 W, powder feed rate of 8 g/min, and scanning speed of 0.4 m/min, 0.5 m/min, and 0.6 m/min. The austenitic phase [Formula: see text] is detected at all the conditions. However, ferrite [Formula: see text] peak is observed at 0.6 m/min due to microsegregation and thermal gradients. The minimum crystallite size is estimated to be 24.88 nm at 0.6 m/min. The porosity and microstructure analysis is carried out by optical microscopic images. The fine columnar dendritic structure is observed in L-DED samples at all conditions. An average microhardness of 317.4 HV0.98 N is obtained at 0.4 m/min, and it is observed that microhardness reduces with an increase in scanning speed mainly due to increase in lack of fusion and porosity. Tribology studies are carried out at different values of normal load and sliding velocity. The minimum specific wear rate of 0.02497 × 10−4 mm3/Nm is observed at scanning speed of 0.4 m/min. Scanning electron microscope of the wear tracks analysis shows abrasive wear as the major wear mechanism. This study provides a path for building SS316 components for various engineering applications.

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Zhao, Tong, Teng Chen, Yuhan Wang, Mengjie Wang, Maha Bakir, Marius Dahmen, Wangcan Cai, et al. "Laser Directed Energy Deposition of an AlMgScZr-Alloy in High-Speed Process Regimes." Materials 15, no. 24 (December 14, 2022): 8951. http://dx.doi.org/10.3390/ma15248951.

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Aluminum-magnesium-scandium-zirconium (AlMgScZr) alloys need to be rapidly cooled from the liquid state to obtain a high degree of solute supersaturation that helps to exploit the precipitation hardening potential of the material. While AlMgScZr alloys have been successfully used in laser powder bed fusion (LPBF) processes, there has been little research in the field of laser directed energy deposition (DED) of the material. The limited previous studies have shown that the performance of AlMgScZr parts fabricated with DED only reached about 60% of that of the parts fabricated with LPBF. In view of breaking through the limitation associated with the process conditions of conventional DED, this work demonstrates the DED of AlMgScZr alloys in high-speed process regimes and elucidates the mechanism of enhancing the hardness and tensile strength of AlMgScZr alloys by increasing the cooling rate by one to two orders of magnitudes, as well as reducing the track overlapping and the porosity of the specimens during the process. A maximum average hardness of nearly 150 HV0.1 and a max. tensile strength of 407 MPa are obtained by using an energy per unit length of 5400 J/m and a powder feed rate per unit length of 0.25 g/m.

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Vundru, Chaitanya, Ramesh Singh, Wenyi Yan, and Shyamprasad Karagadde. "Effect of spreading of the melt pool on the deposition characteristics in laser directed energy deposition." Procedia Manufacturing 53 (2021): 407–16. http://dx.doi.org/10.1016/j.promfg.2021.06.043.

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Dubiel, Beata, and Jan Sieniawski. "Precipitates in Additively Manufactured Inconel 625 Superalloy." Materials 12, no. 7 (April 8, 2019): 1144. http://dx.doi.org/10.3390/ma12071144.

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Laser-based additive manufacturing processes are increasingly used for fabricating components made of nickel-based superalloys. The microstructure development, and in particular the precipitation of secondary phases, is of great importance for the properties of additively manufactured nickel-based superalloys. This paper summarizes the literature data on the microstructure of Inconel 625 superalloy manufactured using laser-based powder-bed fusion and directed energy deposition processes, with particular emphasis on the phase identification of precipitates. The microstructure of Inconel 625 manufactured by laser-based directed energy deposition in as-built condition is investigated by means of light microscopy and transmission electron microscopy. Phase analysis of precipitates is performed by the combination of selected area electron diffraction and microanalysis of chemical composition. Precipitates present in the interdendritic areas of as-built Inconel 625 are identified as MC and M23C6 carbides as well as the Laves phase.

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Singh, Sapam Ningthemba, and Ashish B. Deoghare. "Macrodimensional accuracy of Ti6Al4V parts manufactured by wire-feed high layer thickness continuous laser directed energy deposition." Journal of Laser Applications 35, no. 1 (February 2023): 012003. http://dx.doi.org/10.2351/7.0000870.

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This paper presents a detailed study on the dimensional accuracy of Ti6Al4V parts manufactured by the wire feed laser directed energy deposition process as compared to the design data before any postprocessing, as the majority of the reported research is focused on the mechanical and microstructural properties of the manufactured parts. Due to the large layer thickness (1.2 mm) and high material deposition rate (15 mm/s), smaller rectangular samples were susceptible to more dimensional inaccuracies. Most of the samples have larger dimensions than the design data, which is favorable for postprocessing. Special consideration should be given to the Z axis as the top layer has the most curves on the periphery of the samples due to shrinkage upon cooling. Depositing the material along the periphery of the present layer at the start of each layer minimized the overflow of the molten alloy when the laser is near the edges of the model in each layer. Upon further inspection using an optical microscope and scanning electron microscope analysis, surfaces voids were observed. Only ∼0.5 mm was required to remove from each side to obtain a minimal crack-free flat surface. The microhardness of the samples ranged from 313.64 to 346.17 HV.

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Aydogan, Beytullah, and Himanshu Sahasrabudhe. "Enabling Multi-Material Structures of Co-Based Superalloy Using Laser Directed Energy Deposition Additive Manufacturing." Metals 11, no. 11 (October 27, 2021): 1717. http://dx.doi.org/10.3390/met11111717.

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Cobalt superalloys such as Tribaloys are widely used in environments that involve high temperatures, corrosion, and wear degradation. Additive manufacturing (AM) processes have been investigated for fabricating Co-based alloys due to design flexibility and efficient materials usage. AM processes are suitable for reducing the manufacturing steps and subsequently reducing manufacturing costs by incorporating multi-materials. Laser directed energy deposition (laser DED) is a suitable AM process for fabricating Co-based alloys. T800 is one of the commercially available Tribaloys that is strengthened through Laves phases and of interest to diverse engineering fields. However, the high content of the Laves phase makes the alloy prone to brittle fracture. In this study, a Ni-20%Cr alloy was used to improve the fabricability of the T800 alloy via laser DED. Different mixture compositions (20%, 30%, 40% NiCr by weight) were investigated. The multi-material T800 + NiCr alloys were heat treated at two different temperatures. These alloy chemistries were characterized for their microstructural, phase, and mechanical properties in the as-fabricated and heat-treated conditions. SEM and XRD characterization indicated the stabilization of ductile phases and homogenization of the Laves phases after laser DED fabrication and heat treatment. In conclusion, the NiCr addition improved the fabricability and structural integrity of the T800 alloy.

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Amirabdollahian, Sasan, Faraz Deirmina, Luke Harris, Raveendra Siriki, Massimo Pellizzari, Paolo Bosetti, and Alberto Molinari. "Towards controlling intrinsic heat treatment of maraging steel during laser directed energy deposition." Scripta Materialia 201 (August 2021): 113973. http://dx.doi.org/10.1016/j.scriptamat.2021.113973.

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Zhang, Hang, Zihao Chen, Yaoyao He, Xin Guo, Qingyu Li, Shaokun Ji, Yizhen Zhao, and Dichen Li. "High Performance NbMoTa–Al2O3 Multilayer Composite Structure Manufacturing by Laser Directed Energy Deposition." Materials 14, no. 7 (March 30, 2021): 1685. http://dx.doi.org/10.3390/ma14071685.

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The conventional method of preparing metal–ceramic composite structures causes delamination and cracking defects due to differences in the composite structures’ properties, such as the coefficient of thermal expansion between metal and ceramic materials. Laser-directed energy deposition (LDED) technology has a unique advantage in that the composition of the materials can be changed during the forming process. This technique can overcome existing problems by forming composite structures. In this study, a multilayer composite structure was prepared using LDED technology, and different materials were deposited with their own appropriate process parameters. A layer of Al2O3 ceramic was deposited first, and then three layers of a NbMoTa multi-principal element alloy (MPEA) were deposited as a single composite structural unit. A specimen of the NbMoTa–Al2O3 multilayer composite structure, composed of multiple composite structural units, was formed on the upper surface of a φ20 mm × 60 mm cylinder. The wear resistance was improved by 55% compared to the NbMoTa. The resistivity was 1.55 × 10−5 Ω × m in the parallel forming direction and 1.29 × 10−7 Ω × m in the vertical forming direction. A new, electrically anisotropic material was successfully obtained, and this study provides experimental methods and data for the preparation of smart materials and new sensors.

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Bozeman, Scott C., O. Burkan Isgor, and Julie D. Tucker. "Characterization of Irradiated 309L Stainless Steel Cladding Produced by Laser Directed Energy Deposition." Microscopy and Microanalysis 28, S1 (July 22, 2022): 2068. http://dx.doi.org/10.1017/s1431927622008005.

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Joshi, Sameehan S., Abhishek Sharma, Shashank Sharma, Sangram Mazumder, Mangesh V. Pantawane, Srinivas A. Mantri, Rajarshi Banerjee, and Narendra B. Dahotre. "Cyclic Thermal Dependent Microstructure Evolution During Laser Directed Energy Deposition of H13 Steel." Transactions of the Indian Institute of Metals 75, no. 4 (February 28, 2022): 1007–14. http://dx.doi.org/10.1007/s12666-022-02544-2.

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Savitha, U., V. Srinivas, G. Jagan Reddy, A. A. Gokhale, and M. Sundararaman. "Laser-Based Directed Energy Deposition of Functionally Graded Metal–Ceramic (NiCr–YSZ) System." Transactions of the Indian National Academy of Engineering 6, no. 4 (October 19, 2021): 1111–18. http://dx.doi.org/10.1007/s41403-021-00282-3.

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Journal articles on the topic 'Laser directed energy deposition'

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