Mechanical Properties and Process Improvement of Tungsten Carbide Additively Manufactured with Renewable Biopolymers

The following study presents ongoing work on the mechanical behavior and process improvement of tungsten carbide that is prepared using additive manufacturing of a sustainable polymeric precursor paste. The Taguchi method was implemented to develop a design-of-experiments and analyze the effect of individual honeycomb geometry design parameters on the compressive moduli of samples fabricated via 3D printing of the sustainable paste. The printing gel was known to provide porosity to tungsten carbide samples, which were hypothesized to increase specific strength given the reduction in density that porosity provides. Mechanical properties were of strong interest in this study, but the emergence of deformations during additive manufacturing appeared to result in significant variability during mechanical testing. Consequently, this study also sought to improve the additive process by aiming to achieve a known constant flowrate of the printing gel and adjusting printing nozzle speed to reflect this. Ongoing work includes utilizing the process improvement investigated in this study to refabricate designed honeycomb geometries of tungsten carbide so that they can be reviewed for mechanical properties. Further studies will then compare mechanical properties to tungsten carbide that was not additively manufactured with the sustainable paste and therefore does not exhibit considerable porosity. (C) 2019 The Authors. Published by Elsevier B.V.