Numerical simulation of thermal behavior during laser metal deposition shaping

2008 ◽  
Vol 18 (3) ◽  
pp. 691-699 ◽  
Author(s):  
Ri-sheng LONG ◽  
Wei-jun LIU ◽  
Fei XING ◽  
Hua-bing WANG
2013 ◽  
Vol 380-384 ◽  
pp. 4327-4331
Author(s):  
Kai Zhang ◽  
Lei Wang ◽  
Xin Min Zhang

Laser Metal Deposition Shaping (LMDS) is an emerging manufacturing technique that ensures significant reduction of process time between initial design and final components. The fabrication of fully dense parts with appropriate properties using the LMDS process requires an in-depth understanding of the entire thermal behavior of the process. In this paper, the thermal behavior during LMDS was studied, both numerically and experimentally. Temperature distribution and gradient in the fabricated part were obtained by finite element method (FEM) simulation. The numerical results are in good agreement with the experimental observations. The numerical method contributes to the comprehension and control of the thermal behavior, and may be used to optimize process parameters and predict the thermal response of LMDS fabricated components.


2021 ◽  
Author(s):  
Mauro Murer ◽  
Giovanni Formica ◽  
Franco Milicchio ◽  
Simone Morganti ◽  
Ferdinando Auricchio

Abstract We present a Computational Fluid Dynamics (CFD) framework for the numerical simulation of the Laser Metal Deposition (LMD) process in 3D printing. Such a framework, comprehensive of both numerical formulations and solvers, aims at providing an exhaustive scenario of the process, where the carrier gas, modeled as an Eulerian incompressible fluid, transports metal powders, tracked as Langrangian discrete particles, within the 3D printing chamber. On the basis of heat sources coming from the laser beam and the heated substrate, the particle model is developed to interact with the carrier gas also by heat transfer and to evolve in a melted phase according to a growth law of the particle liquid mass fraction. Enhanced numerical solvers, characterized by a modified Netwon-Raphson scheme and a parallel algorithm for tracking particles, are employed to obtain both e ffi ciency and accuracy of the numerical strategy. In the perspective of investigating optimal design of the whole LMD process, we propose a sensitivity analysis specifically addressed to assess the influence of inflow rates, laser beams intensity, and nozzle channel geometry. Such a numerical campaign is performed with an in-house C++ code developed with the deal.II open source Finite Element library.


Applied laser ◽  
2012 ◽  
Vol 32 (6) ◽  
pp. 510-515
Author(s):  
钦兰云 Qin Lanyun ◽  
王维 Wang Wei ◽  
杨光 Yang Guang ◽  
卞宏友 Bian Hongyou ◽  
佟明 Tong Ming ◽  
...  

2011 ◽  
Vol 295-297 ◽  
pp. 2112-2119
Author(s):  
Yuan Kong ◽  
Wei Jun Liu ◽  
Yue Chao Wang

In order to control the thermal stress of forming process, based on “element birth and death” technology of finite element method, a numerical simulation of three-dimensional temperature field and stress field during multi-track & multi-layer laser metal deposition shaping(LMDS) process is developed with ANSYS parametric design language (APDL). The dynamic variances of temperature field and stress field of forming process are calculated with the energy compensation of interaction between molten pool-powder and laser-powder. The temperature field, temperature gradient, thermal stress field and distribution of residual stress are obtained. The results indicate that although the nodes on different layers are activated at different time, their temperature variations are similar. The temperature gradients of samples are larger near the molten pool area and mainly along z-direction. Finally, it’s verified that the analysis results are consistent with actual situation by the experiments with same process parameters.


Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2050
Author(s):  
Matthias Kahl ◽  
Sebastian Schramm ◽  
Max Neumann ◽  
Andreas Kroll

Laser-based additive manufacturing enables the production of complex geometries viaayer-wise cladding. Laser metal deposition (LMD) uses a scanningaser source to fuse in situ deposited metal powderayer byayer. However, due to the excessive number of influential factors in the physical transformation of the metal powder and the highly dynamic temperature fields caused by the melt pool dynamics and phase transitions, the quality and repeatability of parts built by this process is still challenging. In order to analyze and/or predict the spatially varying and time dependent thermal behavior in LMD, extensive work has been done to develop predictive models usually by using finite element method (FEM). From a control-oriented perspective, simulations based on these models are computationally too expensive and are thus not suitable for real-time control applications. In this contribution, a spatio-temporal input–output model based on the heat equation is proposed. In contrast to other works, the parameters of the model are directly estimated from measurements of the LMD process acquired with an infrared (IR) camera during processing specimens using AISI 316 L stainless steel. In order to deal with noisy data, system identification techniques are used taking different disturbing noise into account. By doing so, spatio-temporal models are developed, enabling the prediction of the thermal behavior by means of the radiance measured by the IR camera in the range of the considered processing parameters. Furthermore, in the considered modeling framework, the computational effort for thermal prediction is reduced compared to FEM, thus enabling the use in real-time control applications.


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