Investigation of structure–mechanical property relationship in fused filament fabrication of the polymer composites

Abstract

Fused filament fabrication (FFF) process is an emerging 3D printing technique primarily used for rapid prototyping in academic and industrial environments. The mechanical properties of these 3D-printed samples are highly anisotropic in nature and depend on various process parameters. Literature suggests that build orientation is a crucial parameter affecting the mesostructural and mechanical properties of these parts. However, there are no existing models that can correlate the mechanical properties of these printed parts with their mesostructural properties. Herein, a multiparametric mathematical model has been developed, establishing a correlation between the tensile strength, neck length, and pore size of the printed parts. An extensive investigation is carried out on six materials, namely acrylonitrile butadiene styrene (ABSplus P430, ABS POLYLAC® PA-757, and LG ABS RS657), polycarbonate (PC), FDM Nylon 12, and PC-ABS alloys printed in two different build orientations (XZ and ZX). The change in mechanical properties with respect to build orientation and the mesostructural properties was examined. It was established that parts printed in the XZ orientation exhibit a higher tensile strength, owing to the higher neck length and smaller pore size. Regression analysis was carried out to develop mathematical models correlating the tensile strength with the mesostructural properties of the printed parts. A good agreement is observed between the theoretically predicted and experimentally found tensile strength.