Effect of surface texturing on friction behaviour of 3D printed polylactic acid (PLA)

Additive manufacturing is gaining a remarkable importance in manufacturing industries because of the ability to build parts with complex and intricate shapes. The most widely used material in additive manufacturing is the polymer. In this paper, circular textures have been 3D printed on the surface of Polylactic Acid (PLA) polymer using fused deposition modelling technique. Experiments were performed under dry and lubricated conditions by varying the texture size. The results were obtained for high and low speeds with varying loads of 10, 20, 30, 40 and 50 N. It was observed that coefficient of friction was minimum for texture T₂ at both high and low speeds under dry sliding conditions. This is due to the less real area of contact than texture T₁ and more effective formation of transfer film in case of texture T_3. The entrapment of wear debris is more effective which helps in the formation of transfer layer that acts as solid lubricant. Under lubricated conditions, it was observed that for low speed, texture T₃ has least coefficient of friction while at high speed texture T₁ resulted in the minimum coefficient of friction. This is mainly due to the more retention of lubricating oil for texture T₃ at low speed in comparison to the high speed. Surface analysis carried out for all the textures under dry sliding conditions revealed that the wear is mainly to adhesive and abrasive action.