Experimental investigation into the fabrication of green body developed by micro‐extrusion‐based 3D printing process

Abstract In the present work, a micro‐extrusion‐based three‐dimensional (3D) printing process has been used to fabricate a metal‐polymer‐based green body. The fabricated parts consisted of carbonyl iron particles with a binder (polylactic acid) and a solvent mixture. From the pilot experiments, it was found that the process parameters, namely, Fe loading, layer thickness , and infill density , affect the green density, shrinkage, and surface roughness of the fabricated part. Moreover, to develop a statistical model with significant factors, experiments were performed based on the design of the experiment using a central composite design method. The experimental results revealed that green density and surface roughness of 3D printed parts increased with the increase in Fe loading and infill density. On the contrary, the shrinkage in the fabricated part decreased with an increase in Fe loading and increased with the rise in infill density. Further, with an increase in layer thickness, the green density decreased while shrinkage and roughness were observed to increase. To verify the accuracy of the developed model, confirmation experiments were also performed at the optimum set of process parameters obtained by the genetic algorithm optimization technique.