67 - NUMERICAL MODEL FOR THE LASER METAL DEPOSITION ADDITIVE MANUFACTURING PROCESS: MULTI-SCALE APPROACH AND EXPERIMENTAL VALIDATION

Abstract

In recent years, the field of Metallic Additive Manufacturing (AdM) technology has experienced significant growth and development. Laser Metal Deposition (LMD) is one of the processes in this growing field. It is based on the injection of metallic powders into a melt-pool created in the part being manufactured by a laser source. It enables direct manufacturing of parts with complex shape geometries with high strength, less material waste and less production steps. However, LMD process is complex and demanding a high level of control to prevent defects from arising. Numerical simulation proves to be a helpful tool to predict the geometry of the molten, including defects, and to optimize process. In this study, a multi-scale approach using the Finite element Method (FEM) is developed to study the issue of modeling a single layer and a multi-layer deposition in the LMD process. This approach is based on chaining two numerical models. A thermal model, at part scale, governs the construction of the entire part and a multi-physics model, at layer scale, dedicated to analyzing the characteristics of the molten pool. Both models are developed to predict thermal conditions during 3D printing process, as well as relations between material deposition and operating parameters. The mass transfer, phase transformations and heat transfer are incorporated in all domains (gas, substrate and melt pool) using the commercial software COMSOL Multiphysics. As a new feature, the developed approach simulates the growth of the track using the generation of droplets when the powder flow is intercepted by the laser beam. Material addition, interface tracking, and strong topological changes are handled using the level set technique. The numerical results are compared to the experimental results for validation purposes. These comparisons include a cross-section of predicted melt pool dimensions and track geometry against experimental data from macrographs and high-speed videos. Then, the developed model is used to optimize operating parameters.

Speaker

Ghassen Dali

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UTC, Compiegne, France

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Conference

67 - NUMERICAL MODEL FOR THE LASER METAL DEPOSITION ADDITIVE MANUFACTURING PROCESS: MULTI-SCALE APPROACH AND EXPERIMENTAL VALIDATION

Date/Time

20/03/2024

11:55 am -12:15 pm

Location

Room 8