Simulação computacional da etapa de sinterização do processo de manufatura aditiva de metais por extrusão de material

Abstract

Due to the increase in production speed and the growth of global competition arising from industry 4.0 and other technological advances in recent decades, companies have been looking for ways to meet their manufacturing demands, whether in order to increase the efficiency of processes, reduce costs or promote the autonomy of the company in its processes. In this context, Additive Manufacturing (AM) emerges as a new horizon, opposing traditional manufacturing methods, usually directed to material removal. This method, carried out by a process of addition, layer by layer, allows the production of parts with complex geometries in a relatively short time, and can help in prototyping or even replace parts and components manufacturing steps. Within the AM, a field that has been popular in recent years is the AM of metals, which is targeted by companies due to the manufacturing materials being used on a large scale in the industry, with emphasis on the automotive industry, a field in which the partner company works. Such use must be mainly due to robustness, resistance and the large number of processes aimed at the use of such materials. The Material Extrusion AM process developed by Markforged® is a metal AM process, consisting of three main steps, printing, debinding and sintering. Due to the low possibility of controlling the parameters of this process, the partner company has been looking for alternatives in order to predict the dimensions and tolerances of the parts experimentally. Some commercial AM process simulation programs have been designed in order to increase the predictability of such processes, among them, the Altair® Inspire™ Print3D program was chosen for the present study, due to having a sintering simulation module for the Binder Jetting (BJT) process. The parameters used were modified in order to get as close as possible to those used in the Markforged® Material Extrusion process. This work aims to compare, dimensionally, the numerical models obtained through sintering simulations, with real parts manufactured by the MA process by Material Extrusion. Note that the simulation obtained good results when the dimensions were compared with those of the printed parts without a raft, reaching a difference in the selected dimensions of the range of 1%. This percentage, however, still reflected in measurements above the defined tolerance. There was also a limitation of the program in predicting warping near the base of the furnace, due to the fixation of the lower face of the geometry on the Z axis. It should also be noted that the raft was presented as a limiting factor due to its use generate a pattern on the lower surface of the manufactured parts, interfering with the measurements and finishing of the parts.