Improvement of thermal, electrical, and tribological performances of GnPs composites produced by selective laser sintering

In the present work, Graphite nanoPlatelets/Polyamide-12 (GnPs/PA-12) particle composites were produced through additive manufacturing (AM). The selective laser sintering (SLS) technology was used to manufacture 3D-printed composite components by means of a powder mix of GnPs and PA-12. The analyzed combination of technology and materials allows to obtain parts with improved thermal, electrical, and tribological properties, while maintaining a low production cost. In total were realized 5 different scenarios, each one with a different wt% of the GnPs reinforcement (2-4-6-8-10 wt%), and compared the results to the PA-12 matrix. Experimental tests were performed to study the morphology (profilometry, SEM, wettability), the electrical conductivity under different normal loads (0.1-1 kN), the thermal performance, and the tribological properties of each sample. The results show that the increase of GnPs particles dispersed in the matrix leads to a hydrophobic behavior of the surface. An improvement in electrical conductivity (from 10-11 S/cm of the pure PA-12 matrix to 10-4 S/cm of the 10 wt% GnPs) and thermal performance (33,6% improvement for the best-case scenario compared to the bare matrix) was observed. Tribological tests underlined a reduction of 25% in friction coefficient and an improvement of 80% in wear resistance compared to the PA-12 matrix.Highlights 3D printed GnPs/PA-12 composites does not exhibit any significant geometrical alteration. GnPs enable hydrophobic surfaces with increased contact angles. Electrical conductivity improved from 10-11 S/cm of the unfilled PA-12 matrix up to 10-4 S/cm, for the 10 wt% GnPs sample. Thermal performance improves up to 33.6% with GnPs reinforcement. 10 wt% GnPs reduces friction by 25% and wear by 81%.