Gas flow study for development of a novel shielding gas nozzle for directed energy deposition processes using computational fluid dynamic simulations
Open Access
- 1 November 2021
- journal article
- research article
- Published by IOP Publishing in IOP Conference Series: Materials Science and Engineering
- Vol. 1135 (1), 012016
- https://doi.org/10.1088/1757-899x/1135/1/012016
Abstract
Directed energy deposition (DED) enables the additive manufacturing of several materials such as molybdenum alloys that are very difficult to process by conventional methods. Some of these materials are highly reactive to gases in ambient atmosphere such as oxygen, and nitrogen. Oxidation during additive manufacturing significantly influences the mechanical properties of a part. In some cases, the shielding gas coverage of standard powder nozzles is not sufficient, and oxidation still takes place. A functional prototype of a compound multi flow path annular nozzle was developed using computational fluid dynamics simulations. Simulations were performed using multi-component miscible gas model. Prototypes were manufactured for several design iterations to test their functionality in cold flow conditions. In the end, an Inconel based prototype was built, using laser powder bed fusion. The volume of shielding gas cover over the substrate improved with the proposed design and the radial extent of 80 ppm oxygen concentration increased from 8 mm to 25 mm. Finally, Mo-Si-B alloy was deposited on a 1000 °C pre-heated substrate without significant oxidation or cracks.This publication has 11 references indexed in Scilit:
- Experimental and Numerical Analysis of Gas/Powder Flow for Different LMD NozzlesMetals, 2020
- Material transitions within multi-material laser deposited intermetallic iron aluminidesAdditive Manufacturing, 2020
- Experimental Analysis of the Shot Peening Particle Stream Using Particle Tracking and Digital Image Correlation TechniquesExperimental Mechanics, 2020
- The Effect of Reynolds Number on Jet in Asymmetric Co-Flows: A CFD StudyInternational Journal of Chemical Engineering, 2018
- Study of the Influence of Shielding Gases on Laser Metal Deposition of Inconel 718 SuperalloyMaterials, 2018
- Design and Manufacturing of a Protective Nozzle for Highly Reactive Materials Processing via Laser Material DepositionProcedia CIRP, 2018
- Flow imbalance and Reynolds number impact on mixing in Confined Impinging JetsChemical Engineering Journal, 2015
- Experimental flow in various porous media and reconciliation of Forchheimer and Ergun relationsExperimental Thermal and Fluid Science, 2014
- Oxidation Behavior of Mo-Si-B In Situ CompositesSolid State Phenomena, 2007
- Prediction of airflow through a vented box by the Darcy–Forchheimer equationJournal of Food Engineering, 2002