Influence of Matrix Material on Impact Properties of Chopped Carbon Fiber-Thermoplastic Composites Made Using FDM/FFF

Abstract

A major applications of thermoplastic additive manufacturing (typically completed using the fused deposition modeling or fused filament fabrication (FDM/FFF) process) is in the production of polymer matrix composites. Several different reinforcing materials have been proposed and studied, a common one of which is chopped carbon fibers (CCF). Most of the published research on the properties and effect of the CCF reinforcement has relied upon a poly(lactic acid) (PLA) matrix, as it has a low and stable melting temperature, low cost, and mixes readily with particulate or chopped reinforcing materials. For commercially available CCF filament for FDM/FFF, the typical fiber content is around 15–25% by volume, with the remainder being the thermoplastic matrix. To better explore the influence of the matrix material on the properties of these materials, this study compares the IZOD impact properties of standard CCF PLA with CCF-reinforced materials using polyamide/nylon (PA), polycarbonate (PC), acrylonitrile butadiene styrene (ABS), and polyethylene terephthalate glycol (PETG) matrices. All cases were printed at full (100%) density. For each material, samples of 5 mm thickness were tested in the Type A (notch in tension) and Type E (notch in compression) configurations. Two print orientations (flat and horizontal) and two raster angles (0–90° and ±45°) were considered for each combination. As required by ASTM D256, the tests were replicated five times each. The results are compared with the major literature for CCF reinforced PLA, as well as benchmark tests using injection molded samples and non-CCF PLA, PA, PC, ABS, and PETG processed by FDM/FFF.