Evaluation of the relevance of melt pool dynamics in Laser Material Deposition process modeling

The melt pool dynamics consideration in the numeric modeling of the Laser Material Deposition (LMD) process can be enormously difficult and expensive, especially if this calculation is not strictly necessary. The increased cost comes mainly from the necessity of considering a higher number of input parameters into the model in addition to the computational cost. Therefore, an analysis of the influence of the melt pool dynamics in a LMD model and its impact on the accuracy is presented. For this purpose, a numeric model that simulates the melt pool fluid-dynamics has been developed and experimentally validated for different situations. After a detailed analysis of the results, an exponential formula based on the response surface methodology (RSM) that quantifies the influence of the fluid-dynamic phenomena inside the melt pool has been obtained. The main conclusion of the present work is that the LMD process can be addresses as a thermal problem without considering the melt pool dynamics and without losing accuracy for a certain window of process parameters, what reduces the computational cost and will allow an easier integration of the model in CAE tools for process simulation. (C) 2017 The Authors. Published by Elsevier Ltd.