Combined Effects of Thermal Cycling Aging and Reinforcement Content on the Ball‐On‐Disk Wear of Additively Manufactured Polylactic Acid Composites

ABSTRACT

This study focuses on the additive manufacturing of pure polylactic acid (PLA) specimens and milled glass fiber (GF)‐filled PLA composites under thermal cycling aging and wear tests. Wear tracks have been analyzed via 3D optical profiling and SEM imaging. DSC was used to characterize the material changes caused by thermal cycling rather than to determine friction‐induced heating or thermal softening during the wear tests. Factorial ANOVA has been used to evaluate the contribution of different factors. Reinforcement of PLA decreased wear depth in case of 50 mm s ⁻¹ sliding speed in all aging cases; 15 wt% GF lowered wear depth to 81 μm from 217 μm for pure PLA after 400 aging cycles. Under maximum aging and sliding speed of 100 mm s ⁻¹ , wear resistance has been degraded due to the degradation of interface and fiber pull‐out that promoted the third body abrasive wear; hence aged 10 wt% GF composite was the most worn specimen. ANOVA found material composition as the main factor affecting wear depth (34.67%), while interaction factors affected friction coefficient (61.54%).