Effect of graphite on tribological and mechanical properties of PA6/5GF composites

Polyamide 6 (PA6)-based composite materials have shown attractive mechanical properties for structural applications. However, their tribological properties have not been much improved till date. Therefore, influence of graphite (Grt) with variation of 1, 3, and 5 mass% on the mechanical and tribological behaviours of 5 mass% glass fibre (GF)-reinforced injection moulded PA6 composites has been studied. This study describes the fabrication and experimental evaluation of Grt-reinforced PA6/GF composites (e.g., PA6/5GF/1Grt, PA6/5GF/3Grt, and PA6/5GF/5Grt). The coefficient of friction (COF) and dry wear properties were evaluated under ambient conditions at variable rotating speeds of 200, 400 and 800 rpm, and normal loads of 10, 20 and 30 N for a fixed run-time of 30 min. SEM and optical microscopy revealed the morphology and wear mechanisms of worn surfaces. Among all the developed composites, 1 mass% of graphite-reinforced PA6/5GF composite had shown noticeably enhanced the tribological (0.20-0.26 COF) and mechanical (45 MPa tensile strength and HRB 47 hardness) characteristics compared to pure PA6, other prepared composites and also some other reported similar composite systems. The thermogravimetric analysis revealed that the optimal thermal stability can be achieved by PA6/5GF/1Grt composite, which, thus, can be used for further applications.