Effect of print orientation and bronze existence on tribological and mechanical properties of 3D-printed bronze/PLA composite

Abstract

In this work, fused deposition modeling (FDM) technology is employed for manufacturing tribological and tensile testing specimens. The test pieces are fabricated in diverse directions to examine the influence of print orientation. The tribological tests are carried out in reciprocating sliding and under dry condition. Due to their relevance, the surface roughness and the hardness of the products are studied as well. Many images are captured under a microscope to better understand the surface morphology of 3D-printed parts before and after testing. The findings reveal that the existence of various print orientations determines differences in mechanical properties and tribological behavior. Among the investigated parameters, the one with the highest tensile strength at break point is the On-Edge print orientation. The vertically oriented test pieces offer the highest friction tendency but the lowest wear depth. Meanwhile, less wear is observed when sliding under low loads but the tendency for stick-slip phenomenon occurrence increases. Although PLA is presently one of the most popular filaments for 3D printing, it can be employed in some industrial applications (e.g., bushings and bearings), if the tribological properties are amended. Bronze is characterized by excellent sliding capability because of its very low metal-on-metal friction. To date, very limited attention has been given to research on the tribology of 3D-printed objects. Therefore, the purpose of the current work is to fill the gap in knowledge by being the first study to evaluate the impact of bronze presence and 3D printing orientation on the tribological properties of bronze/PLA composite.