Compressive characterisation of 3D printed composite materials using continuous fibre fabrication

Abstract

A variety of 3D printing parameters have been investigated including reinforcement material and print orientation, as well as reinforcement pattern, distribution and volume. From these evaluated parameters, the optimal values are taken into account to select the highest compressive properties. By using Scanning Electron Microscopy (SEM) imaging, reinforcement and thermoplastic layers have been clearly identified alongside sample flaws. Horizontally printed samples exhibited higher mean values with less standard deviation than vertically printed ones for compressive modulus and compression strength. For the sample set with the Nylon and carbon fibre; concentric and isometric fill patterns were compared in three different fibre distributions. Concentric fill pattern with equidistantly fibre distribution exhibited the highest compressive modulus as 1.8 GPa. It also exhibited a higher proportional limit of 12.80% and compressive modulus of 11.64% than its counterpart with the isometric fill pattern.For the set with 12.5% fibre volume, Onyx + CF (matrix + reinforcement) exhibited higher compressive modulus and compressive strength than Nylon + CF by 18.5%, and 28.1%, respectively. Within the experimental set of different reinforcements (carbon fibre, Kevlar, fibreglass), and different fibre volumes (6.25%, 12.5%, 25%) with Onyx matrix; Onyx thermoplastic with fibreglass reinforcements and a fibre volume of 25% exhibited the highest compressive properties.