Orientation controls tribological performance of 3D-printed model thermoplastics

Abstract

Additive manufacturing is rapidly growing in popularity due to its capability to produce parts with customized mechanical properties. Recent studies show that mechanical properties can be altered in a controlled manner by adjusting the relationship between build orientation and the applied loading from the service. In this work, the effect of build orientation on the tribological properties of 3D printed PLA – Polylactic acid and ABS- Acrylonitrile butadiene styrene is investigated. PLA and ABS samples are printed using material extrusion with three different build orientations. Tribological results show that variation in build direction relative to the sliding direction leads to anisotropic wear properties. The best wear properties are achieved when the layers are oriented orthogonally to the sliding direction. The coefficient of friction remains mostly unaffected by the build orientation. PLA samples demonstrate significantly better tribological properties compared to ABS. Varying the sliding speed between the interacting surfaces also affects the wear properties of both PLA and ABS. The results suggest that optimizing the build orientation with respect to service loading can improve the wear performance of additively manufactured thermoplastics. This presents an additional paradigm when designing additively manufactured parts potentially for functionally graded materials.