Producing metallic parts using 3D printing of low-viscosity powder-binder feedstock: A feasibility study

• Main Authors: Côté, Raphaël, Demers, Vincent, Demarquette, Nicole R., Charlon, Sébastien, Soulestin, Jérémie
• Format: Conference Proceeding
• Language: English
• Subjects: Adhesives; Dimensional stability; Ethylene vinyl acetates; Feasibility studies; Organic binders; Paraffin wax; Process parameters; Raw materials; Stainless steels; Stearic acid; Three dimensional printing; Viscosity
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0168410

The possibility to fabricate metallic parts by material extrusion additive manufacturing of highly-filled polymer (MEAM-HP) with low-viscosity feedstock has been demonstrated in this study. Quality parts were successfully printed using a laboratory plunger-based printer and two feedstocks consisting of stainless-steel powder blended with two different compositions of organic binders made of ethylene-vinyl acetate (EVA), paraffin wax, and stearic acid. Using the first feedstock, containing 5 vol. % EVA, dimensionally stable parts were printed only for a feedstock temperature of 70 °C, while with the second feedstock, containing 10 vol. % EVA, stable parts were printed within a larger feedstock temperature range of 70 to 140 °C. The minimum feedstock temperature was defined at 85 °C to guarantee sufficient adhesion between beads and limit binder shrinkage during the cooling. Using this optimal process parameter, complex-shape parts were successfully printed confirming that complex surfaces, bridging, and overhang structures can be produced using low-viscosity feedstock without help of supports.