Comparative Study on the Wear Properties of Fly Ash and Silica Fume Filled Nylon Composites

Nylon 66 is an engineering thermoplastic which has been found to be a suitable alternative material for metal parts in low and medium load bearing applications. Particulate filled polymer composites are preferred in this kind of tribological environment, because of their enhanced wear resistance properties. Fly ash and silica fume are industrial wastes which are now looked as potential fillers to enhance the material properties at low cost. Nylon 66 was reinforced with these filler materials at 15% weight fraction using a twin-screw extruder. The specimens were prepared using an injection molding machine of 60 ton capacity. The tests were carried out under dry sliding conditions in a pin-on-disc type friction and wear monitoring test rig. The tests were conducted at various sliding velocities of 2 m/s, 3 m/s and 4 m/s, at three different normal loads of 20 N, 40 N, 60 N and at a constant sliding distance of 5000 m. SEM observations were made to study the wear mechanisms in the composites. Both types of composites showed enhanced wear properties compared to neat Nylon but fly ash filled Nylon composites were superior to silica fumed filled Nylon composites.