Experimental investigation of tribological behavior of FDM-PLA surfaces

In the present study, the tribological behavior of 3D printed components manufactured with different raster orientations [0°/90°], [+15°/−75°], [+30°/−60°] and [+45°/−45°] was evaluated. Special attention was given to the impact of raster orientation on roughness parameters, particularly in the mean spacing of the profile <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msub> <mml:mi>R</mml:mi> <mml:mrow> <mml:mi>s</mml:mi> <mml:mi>m</mml:mi> </mml:mrow> </mml:msub> </mml:math> and the arithmetic average roughness <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msub> <mml:mi>R</mml:mi> <mml:mi>a</mml:mi> </mml:msub> </mml:math> . Experiments were conducted on Polylactic Acid (PLA) using a reciprocated tribometer apparatus under two contact pressures <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msub> <mml:mi>P</mml:mi> <mml:mn>1</mml:mn> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>27</mml:mn> <mml:mrow> <mml:mi mathvariant="normal">MPa</mml:mi> </mml:mrow> </mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msub> <mml:mi>P</mml:mi> <mml:mn>2</mml:mn> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>59</mml:mn> <mml:mrow> <mml:mi mathvariant="normal">MPa</mml:mi> </mml:mrow> </mml:math> . The friction force was measured and recorded during the test. Furthermore, 3D optical profilometric analyses were conducted to characterize the wear mechanisms. The crater area <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msub> <mml:mi>S</mml:mi> <mml:mo>−</mml:mo> </mml:msub> </mml:math> and the track width W were also measured in order to investigate the wear evolution. Experimental results show that, under low load, the change of the raster orientation from [+45°/−45°] to [0°/90°] reduces the friction coefficient by ∼ 71% and decreases the track width W by ∼ 41%.