Experimental and numerical analysis of effects of supercritical carbon dioxide debinding on Inconel 718 MIM components

Abstract

Polymer extraction is a key step of the metal injection moulding (MIM) process. An innovative method for extracting an organic binder involves the use of supercritical fluid instead of a regular solvent. The supercritical fluid selected was carbon dioxide due to its affinity toward polyethylene glycol. The supercritical carbon dioxide parameters were optimised in order to complete the extraction of this polymer from the Inconel 718 superalloy feedstock. The effects on the surface quality of the components and on the microstructure of the densified component were also investigated. A finite element model, which combines the fluid model and structural mechanics , enabled the estimation of the stress distribution during the supercritical debinding step. The study was completed by a parametric analysis of the pressure variation inside the equipment with respect to the processing parameters for the MIM components.

Design of Sustainable Aluminium-Based Feedstocks for Composite Extrusion Modelling (CEM)

“…Machinery, Peotonoe, IL, USA) at 170 °C with an injection time of 6 s and a pressure of 7 bar. To ensure the structural integrity of the samples, and taking into account previous studies with a similar binder system [ 26 ], a two-stage debinding process was performed. The first was a debinding cycle in water at 60 °C with continuous agitation and different immersion times (5 h, 7.5 h, and 10 h) for the removal of PEG from the green parts.…”

An Automated Open-Source Approach for Debinding Simulation in Metal Extrusion Additive Manufacturing

“…Nevertheless, both simulation methods give no information on the material behavior after debinding nor the structural integrity of the debindered part and also extensive input data has to be acquired for running the simulations. Besides the work in [19], where stress distributions during debinding are simulated using fluid-structure interaction simulations, stress distribution during debinding or material behavior after debinding are barely considered. This is due to the fact normally, classical PIM applications are produced in very large volumes, and the final geometry and orientation is either determined experimentally or based on experience.…”