Frictional Behaviors of 3D-Printed Polylactic Acid Components With Spiral-Groove Surface Textures Under Oil Lubrication

With the rapid development in additive manufacturing technology, three-dimensional (3D) printing process has been extensively utilized for the prototype manufacturing of industrial components. It is becoming possible and fascinating to directly fabricate surface textures for tribological applications by 3D printing. In this study, a series of polylactic acid (PLA) components with spiral-groove surface textures for the application prospect in the field of mechanical seals were fabricated on a commercially available fused deposition modeling (FDM) 3D printer. The frictional behaviors of the printed components under oil lubrication were investigated on an end-face tribometer. The influence of spiral groove number, groove depth, and printing orientation on friction coefficients was discussed. The test results indicate that the frictional performance of linear-printed component with small groove depth is much better than that of homocentric-printed ones with large groove depth. The minimum average friction coefficient of linear-printed component is about 0.07 while the value is about 0.085 for the homocentric-printed ones. In final, a theoretical simulation based on the Reynolds lubricating regime was conducted to clarify the underlying mechanism of the experimental results, and the numerical results show that the hydrodynamic effect of the linear-printed components is more obvious due to the interaction between the linear printing clearances and the rotation of the counterpart.