Effect of composite processing technique on tribological properties of 3D printed PLA-graphene composites

The present study investigates the effect of processing method on the tribological behavior of 3D-printed Polylactic acid (PLA)/graphene composite samples. Two different methods, electrochemical (EG) and chemical exfoliation (HG) of graphite, are used to prepare graphene fillers. The PLA/graphene composites are processed using two different solvents, chloroform (CHCl3) and dimethylformamide (DMF). Various PLA/graphene composite combinations are prepared by varying filler type, solvent type, and filler loading. The 3D printable composite feedstock filaments are prepared using a single-screw Desktop extruder. Fused Filament Fabrication (FFF) is employed to print samples for tribological tests. The coefficient of friction (COF) and wear rate are evaluated using the ball-on-flat reciprocating sliding wear tests. It was observed that COF was reduced by 76% with 0.5 wt. % loading of filler. The wear mechanism has changed from predominant abrasive wear in neat PLA to adhesive wear for composites. Further, the interactive effect of process parameters is studied using ANOVA. The results indicate that filler type and filler loading significantly influence weight loss. The solvent type has a minimum effect.