scholarly journals Spectroscopic monitoring of laser blown powder directed energy deposition of Alloy 718

2018 ◽  
Vol 25 ◽  
pp. 418-425 ◽  
Author(s):  
Agnieszka Kisielewicz ◽  
Fredrik Sikström ◽  
Anna-Karin Christiansson ◽  
Antonio Ancona
Keyword(s):  
Energy Deposition ◽  
Alloy 718 ◽  
Spectroscopic Monitoring ◽  
Directed Energy Deposition ◽  
Directed Energy ◽  
Blown Powder

THERMAL MONITORING AND MODELING OF TI-6AL-4V THIN WALL TEMPERATURE DISTRIBUTION DURING BLOWN POWDER LASER DIRECTED ENERGY DEPOSITION

2021 ◽  
pp. 1-19
Author(s):  
Basil Paudel ◽  
Garrett Marshall ◽  
Scott M. Thompson
Keyword(s):  
Steady State ◽  
Temperature Distribution ◽  
Energy Deposition ◽  
Thermal Capacity ◽  
Thin Wall ◽  
Thin Walled Structures ◽  
Melt Pool ◽  
Directed Energy Deposition ◽  
Directed Energy ◽  
Blown Powder

Abstract The effects of Ti-6Al-4V part size on its temperature distribution during the blown-powder directed energy deposition (DED) process was investigated through dual-thermographic monitoring and a unique modeling technique. Results demonstrate that the duration of dwell times presented to be a significant contributing factor affecting the rate at which a steady-state temperature field is achieved. As a result, the longer wall took significantly more layers/time to achieve a uniform temperature profile within the wall. Maximum and average melt pool temperatures appear to be near independent of part size at a steady state. Finite element simulation results showed that a quasi-steady melt pool temperature may be unique to a layer, especially during earlier cladding process near the substrate and that the layer-wise steady melt pool was achieved within the first few seconds of track scanning. A proposed fin modeling-based temperature distribution was found to predict the thermal profile in a ‘substrate affected zone’ (SAZ) along the scan direction within 5%. A method to predict the onset of the SAZ has also been proposed. Process parameters used for the DED of component volumes are not necessarily optimal for thin-walled structures due to significantly less thermal capacity.

Thermal Monitoring and Modeling of Ti-6Al-4V Thin Wall Temperature Distribution During Blown Powder Laser Directed Energy Deposition

2021 ◽  
Author(s):  
Basil J. Paudel ◽  
Garrett J. Marshall ◽  
Scott M. Thompson
Keyword(s):  
Steady State ◽  
Temperature Distribution ◽  
Energy Deposition ◽  
Thermal Capacity ◽  
Thin Wall ◽  
Thin Walled Structures ◽  
Melt Pool ◽  
Directed Energy Deposition ◽  
Directed Energy ◽  
Blown Powder

Abstract The effects of Ti-6Al-4V part size on its temperature distribution during the blown-powder directed energy deposition-laser (DED-L) process was investigated through dual-thermographic monitoring and a unique modeling technique. Results demonstrate that the duration of dwell times are a significant contributing factor affecting the rate at which a steady-state temperature field is achieved. Longer walls took significantly more layers/time to achieve a uniform temperature profile. Maximum and average melt pool temperatures appear to be near independent of part size at a steady state. Finite element simulation results show that a quasi-steady melt pool temperature may be unique to a layer, especially for layers near the substrate. Layer-wise steady melt pool temperatures were achieved within the first few seconds of track scanning. A proposed fin modeling-based temperature distribution was found to predict the thermal profile in a ‘substrate affected zone’ (SAZ) along the scan direction within 5%. A method to predict the onset of the SAZ has also been proposed. Process parameters used for the DED-L of component volumes are not necessarily optimal for thin-walled structures due to their significantly lower thermal capacity.

Structural Integrity Assessments for Validating Directed Energy Deposition Repairs of Integrally Bladed Rotor

2020 ◽  
Author(s):  
Onome Scott-Emuakpor ◽  
Brian Runyon ◽  
Tommy George ◽  
Andrew Goldin ◽  
Casey Holycross ◽  
...  
Keyword(s):  
Energy Deposition ◽  
Structural Integrity ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
Component Level ◽  
Integrity Assessment ◽  
Repair Processes ◽  
Directed Energy Deposition ◽  
Directed Energy ◽  
Blown Powder

Abstract Considerable steps to assess the structural capability of laser directed energy deposition (DED) aim to determine the viability of repair processes for integrally bladed rotors (IBRs). Two laser DED processes are under investigation in this study: wire fed and blown powder feedstock. Using a small subsonic Titanium 6Al-4V fan as the component of interest, a series of tests and associated models for laboratory specimens, subcomponents, and components are necessary for proper assessment of material structural properties pertaining to the intended mission of the IBR. Experimentation on laboratory specimens acquire properties such as tensile strength, elongation, low cycle fatigue (LCF), high cycle fatigue (HCF), crack growth rate, and fracture toughness. Subcomponent test articles fabrication occurs by sectioning an operational IBR into individual blades for vibration HCF assessment. Component level testing focuses on LCF and overspeed strength acquired from spin rig testing. Even though the full IBR repair validation of laboratory specimen, subcomponent, and component testing has yet to be completed, the results to-date for laser DED repairs are promising. Furthermore, this plan for structural integrity assessment can serve as a reference for validation of future IBR repair processes.

Tailoring alloy 718 laser directed energy deposition process strategies for repair applications

2022 ◽  
Vol 34 (1) ◽  
pp. 012018
Author(s):  
Cory D. Jamieson ◽  
Marissa C. Brennan ◽  
Todd J. Spurgeon ◽  
Stephen W. Brown ◽  
Jayme S. Keist ◽  
...  
Keyword(s):  
Energy Deposition ◽  
Deposition Process ◽  
Alloy 718 ◽  
Directed Energy Deposition ◽  
Directed Energy

scholarly journals Strategy Development for the Manufacturing of Multilayered Structures of Variable Thickness of Ni-Based Alloy 718 by Powder-Fed Directed Energy Deposition

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1280
Author(s):  
Pedro Ramiro ◽  
Mikel Ortiz ◽  
Amaia Alberdi ◽  
Aitzol Lamikiz
Keyword(s):  
Variable Thickness ◽  
Energy Deposition ◽  
Deposition Process ◽  
Strategy Development ◽  
Main Process ◽  
Alloy 718 ◽  
Manufacturing Strategy ◽  
Multilayered Structures ◽  
Directed Energy Deposition ◽  
Directed Energy

In this study, a manufacturing strategy, and guidelines for inclined and multilayered structures of variable thickness are presented, which are based on the results of an own-developed geometrical model that obtains both the coating thickness and dilution. This model is developed for the powder-fed directed energy deposition process (DED) and it only uses the DED single-track cladding characteristics (height, width, area, and dilution depth), the overlap percentage, and the laser head tilting-angle as inputs. As outputs, it calculates both the cladding geometry and the dilution area of the coating. This model for the Ni-based alloy 718 was improved, based on previous studies of the single clad working both vertically and at an inclined angle, adding the equations of the single clad characteristics with respect to the main process parameters. The strategy proposed in this paper for multilayered cladding consisted of both adding an extra clad at the edges of the layer and using a variable value of the overlap percentage between clads for geometric adaptations. With this strategy, the material deposition is more accurate than otherwise, and it shows stable growth. Manufacturing a multilayered wall of wider thicknesses at higher heights was utilized to validate the strategy.

scholarly journals Blown powder directed energy deposition on various substrate conditions

2022 ◽  
Vol 73 ◽  
pp. 660-667
Author(s):  
Himani Naesstroem ◽  
Frank Brueckner ◽  
Alexander F.H. Kaplan
Keyword(s):  
Energy Deposition ◽  
Directed Energy Deposition ◽  
Directed Energy ◽  
Blown Powder

scholarly journals In-process spectroscopic detection of chromium loss during Directed Energy Deposition of alloy 718

2020 ◽  
Vol 186 ◽  
pp. 108317 ◽  
Author(s):  
Agnieszka Kisielewicz ◽  
Esmaeil Sadeghi ◽  
Fredrik Sikström ◽  
Anna-Karin Christiansson ◽  
Gianfranco Palumbo ◽  
...  
Keyword(s):  
Energy Deposition ◽  
Alloy 718 ◽  
Directed Energy Deposition ◽  
Directed Energy

scholarly journals Effects of Gravity and Non-Perpendicularity during Powder-Fed Directed Energy Deposition of Ni-Based Alloy 718 through Two Types of Coaxial Nozzle

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 560 ◽  
Author(s):  
Pedro Ramiro-Castro ◽  
Mikel Ortiz ◽  
Amaia Alberdi ◽  
Aitzol Lamikiz
Keyword(s):  
Energy Deposition ◽  
Horizontal Displacement ◽  
Alloy 718 ◽  
System Configuration ◽  
Directed Energy Deposition ◽  
Coaxial Nozzle ◽  
Complete Study ◽  
Directed Energy ◽  
Main Effects ◽  
Do So

The consequences of gravity and the nozzle inclination angle in the powder-fed Directed Energy Deposition (DED) process were examined in this study. We also sought to define guidelines and manufacturing strategies, depending on the DED system configuration and the nozzle type. To do so, two nozzle types were used: a continuous coaxial nozzle with a slit of 0.5 mm and a four-stream discrete coaxial nozzle. Although the main effects of the configurations and the nozzles are well-known, their effects on the clad characteristics and the deposition strategy are as yet unclear. In this paper, measurements of a single clad and the effects of different deposition strategies on cladding applications and inclined walls are presented, and the consequences for manufacturing processes are discussed. Based on a complete study of a single clad, working vertically, five different tilted deposition strategies were applied: three to a single clad and two to an inclined wall. The results for both the single clad and the inclined wall reflect a pattern of changes to height, width, area, and efficiency, at both small and large nozzle angles and deposition strategies. The inclined wall presents a maximum horizontal displacement that can be reached per layer, without geometrical distortions. The amount of material per layer has to be adapted to this limitation.

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