Simulation of Laser-assisted Directed Energy Deposition of Aluminum Powder: Prediction of Geometry and Temperature Evolution

Abstract

One of the main current challenges in the field of additive manufacturing and directed energy deposition of metals, is the need for simulation tools to prevent or reduce the need to adopt a trial-and-error approach to find the optimum processing conditions. A valuable help is offered by numerical simulation, although setting-up and validating a reliable model is challenging, due to many issues related to the laser source, the interaction with the feeding metal, the evolution of the material properties and the boundary conditions. Indeed, many attempts have been reported in the literature, although some issues are usually simplified or neglected. Therefore, this paper is aimed at building a comprehensive numerical model for the process of laser-assisted deposition. Namely: the geometry of the deposited metal is investigated in advance and the most effective reference shape is found to feed the simulation as a function of the governing factors for single- and multi-track, multi-layer deposition; then, a non-stationary thermal model is proposed and the underlying hypotheses to simulate the addition of metal are discussed step-by-step. Validation is eventually conducted, based on experimental evidence. Aluminum alloy 2024 is chosen as feeding metal and substrate.

A data-driven framework to predict the morphology of interfacial Cu6Sn5 IMC in SAC/Cu system during laser soldering

“…The first term in the right-hand side (RHS) of Eq.4 is the thermal convection term, and kth is the thermal conductivity of the solder alloy. The second term in the RHS of the heat equation is the heat source term due to laser irradiation, and thus Qlaser is the laser heat generation [30] . Assuming the intensity profile of the laser beam exhibits the Gaussian function, and the laser material interaction is characterized by Beer's law, Qlaser for the context of 2D simulation, can be expressed by the following equation [31]:…”

Estimation Method of Interpass Time for the Control of Temperature during a Directed Energy Deposition Process of a Ti–6Al–4V Planar Layer

“…Directed energy deposition (DED) is a metal additive manufacturing technology that uses a high-intensity heat source to melt and fuse metallic feedstock to substrate as they are being fed. It has shown promising applications for the production of large metallic components and the repair of the damaged region of an existing part [1][2][3]. In the case of remanufacturing and repairing a component, molding, or forming tool using the DED process [4][5][6][7][8], the ability to selectively deposit planar layers on the designated location of an existing substrate is crucial.…”

“…With proper process parameters such as laser power, traverse speed, and substrate temperature, a high quality of hard and wear resistance material can be additively manufactured [9]. A planar layer can be augmented to the existing substrate by depositing tracks of metals side by side [3,4]. A three-dimensional object is fabricated by stacking multiple planar layers in a vertical build direction.…”

“…A three-dimensional object is fabricated by stacking multiple planar layers in a vertical build direction. It is expected that high value large-scale industries such as aerospace and automotive will benefit significantly from the development of DED [3].…”

“…Investigation of the influencing factors using numerical analyses has recently become prominent to significantly reduce the number of experimental trial-and-error run in the search for the optimum process parameters of a DED process [3,5,[11][12][13]. These process parameters are determined based on simulation results of one or more combinations of temperature distributions [14][15][16], thermo-mechanical characteristics [17][18][19][20][21], and microstructure evolution [1,22].…”