Combined surface treatment and graphene coating strategies for enhanced performance of 3D printed ABS components

The aim of this study is to evaluate the possibility of modifying the mechanical and surface properties of components made of acrylonitrile butadiene styrene (ABS) by means of material extrusion (MEX) 3D printing technology, in the context of possible industrial applications such as the realization of heat sinks and electromagnetic interference (EMI) shields. In fact, MEX technology is particularly advantageous in prototyping and industrial fields, as it allows producing reasonably complex parts with low cost and huge materials choice in several industrial sectors. The MEX printing process, however, is closely linked to the use of thermoplastic polymer filaments that almost retain the initial geometry after the printing step. The present study involves the evaluation and combination of different surface treatment strategies and their effectiveness in reducing roughness and waviness of 3D printed samples. Smoothing treatments in acetone and mechanical treatments such as polishing and sandblasting were examined. A resin-graphene composite coating was applied on treated samples to modify the wear resistance, thermal, and electrical conductivity properties of the ABS molded part. The effect of the specific substrate treatment on the performance of resin-graphene coating was then studied. It emerged that surface treatments could promote coating adhesion and its effective distribution on sample surface. The graphene-based coating, applied to treated substrates, modified the properties of the molded material. The wear resistance of the coating applied on polished ABS increased the wear resistance by 75% with a 52% reduction in the friction coefficient. Compared to the as-printed sample, thermal performance increased 104% for the acetone-dip scenario. Furthermore, all the coated samples exhibited remarkable electrical conductivity.