Mechanically robust and abrasion-resistant polymer nanocomposites for potential applications as advanced clearance joints

Abstract

Despite exceptional dimensional stability, polyamide 6 (PA6) still suffers relatively low mechanical strength and stiffness as compared with metallic and ceramic materials, which thus significantly limits its engineering applications. Herein, we have demonstrated the fabrication of high-performance PA6 composites with excellent mechanical and wear resistance by introducing nanoscale silicon carbide (SiC) as the reinforcer and anti-wear agents. The results show that the addition of 5 wt% nanoscale SiC (NS) increases the tensile strength of PA6 by 54% (reaching 64.8 MPa) while the elongation at break is over 6 times (around 304%) of that of the PA6 matrix, which giving rise to a 9.6 times increase in the fracture toughness. Moreover, the addition of 30 wt% of NS reduces the friction coefficient from 0.31 for the PA6 to 0.12, indicating improved anti-wear performances. Such significant improvements in both mechanical and anti-wear properties are primarily due to the high stiffness of NS and the strong interfacial interactions with the PA6 matrix. In addition, the effects of friction coefficient on dynamic characteristics of mechanism with clearance are also investigated to gain an insightful understanding on the improved anti-wear properties. This work provides a facile approach to the design of advanced polymer composites combining excellent mechanical and anti-wear performances.