Post-processing technologies of copper–polylactic acid composites obtained by 3D printing fused deposition modeling

Abstract

The goal of the present study is to obtain a new structured material starting from a copper–polylactic acid (PLA) composite filament 3D printed using fused deposition modeling method, followed by a sintering process in vacuum atmosphere. Metal-reinforced filaments made of 80 wt.% copper encased in an environmentally friendly, biodegradable and carbon neutral PLA binder were used as feedstock materials. The thermal stability and the melting temperature of the filaments were evaluated through thermogravimetric analysis. The printing parameters were chosen according to the producer's specifications. Furthermore, the printed samples were submitted to a two-step sintering process in a vacuum furnace, assuring a complete removal of the polymeric material and the diffusion of the copper particles. The post-treatment revealed a porous structured material, similar to a cellular solid. Microstructural analysis and preliminary mechanical testing show that the porosity and hardness of the end product are heavily influenced by the initial polymer content.