Effects of re-entrant auxetic structure on friction-induced vibrational behaviour of 3D printed PLA in sliding wear process

The present research investigates the effects of re-entrant auxetic structure’s on friction-induced vibrational behaviour of three-dimensional (3D) printed polylactic acid (PLA) samples. A series of re-entrant auxetic specimens with different re-entrant angles were prepared for sliding wear tests. The results showed that with the increase in re-entrant angles, the negative Poisson ratio becomes greater. Accordingly, the specimen showed less vibration during the sliding wear process, with a lower average friction coefficient. As a result, the wear resistance of the specimens with embedded re-entrant structures was clearly improved. Microscopic images revealed that surface fatigue wear was effectively prevented with the re-entrant structures, thanks to their energy absorption and vibration insulation capacities. The findings demonstrated that 3D printing technology could provide a new route for the design and fabrication of high wear resistant engineering components by creating complex functional structures to control and optimize their dynamic behaviour and, thus tribological performance.