Investigation of the properties of polyamide 66 composites with fiber and solid lubricant

In this study, PA66/CE composites were fabricated by incorporating 30 wt% and 40 wt% glass fiber (CE) into the polyamide 66 (PA66) matrix. In addition, binary and ternary PA66 composites were produced through the incorporation of molybdenum disulfide (MoS₂) and polytetrafluoroethylene (PTFE) as solid lubricants. To evaluate the mechanical properties of neat PA66 and its composites, tensile and hardness tests were conducted, while density measurements were performed to determine the physical properties. Wear and friction tests were carried out using a pin-on-disk tribometer under applied loads of 30, 40, and 50 N, sliding velocities of 0,5, 1,0 and 1,5 m/s, and a constant sliding distance of 1000 m. The experimental results revealed that the addition of glass fiber at different loadings enhanced the tensile strength of PA66 by 90,56% and 127%, respectively, whereas the incorporation of PTFE and MoS₂ solid lubricants reduced the tensile strength by 16,93% and 15,28%, respectively. While the addition of MoS₂ and PTFE to neat PA66 decreased the elongation at break, their incorporation into PA66/30CE and PA66/40CE composites resulted in an increase in elongation at break. It was also observed that the coefficients of friction of PA66 and its composites increased with applied load and sliding velocity. Among the solid lubricants, MoS₂ was found to be more effective than PTFE in enhancing both the mechanical and tribological performance of the composites. The lowest coefficient of friction and the highest wear resistance were obtained in the PA66/MoS₂ composite.