Shihua Zhang

Tribological behavior of MC Nylon6 composites filled with glass fiber and fly ash

To improve tribological property of MC Nylon6, the glass fiber and fly ash reinforced monomer casting nylon composites (GFFAPA) were prepared by anionic polymerization of ɛ-caprolactam. The friction and wear behaviors of composites under dry condition, water lubrication and oil lubrication were investigated through a ring-black wear tester. Worn surfaces were analyzed using a scanning electron microscope. The experimental results show that the tensile strength and hardness of nylon composites are obviously improved with reinforcement increasing. Compared to MC nylon, the lowest friction coefficient and wear rate of glass fiber reinforced nylon composites (GFPA) with GF30% respectively decrease by 33.1% and 65.3%, of fly ash reinforced nylon composites (FAPA) with FA20% decrease by 5.2% and 68.9% and of GFFAPA composites with GF30% and FA10% decrease by 57.8% and 89.9%. The main wear mechanisms of FAPA composites are adhesive and abrasive wear and of GFPA composites with high proportion are abrasive and fatigue wear. The worn surfaces of GFFAPA composites are much multiplex and the optional distributing glass fiber and fly ash have a synergetic effect on the wear resistance for GFFAPA composites. Compared with dry friction, the friction coefficient and wear rate under oil lubricated conditions decrease sharply while the latter reversely increase under water lubricated conditions. The wear mechanisms under water lubricated condition are principally chemical corrosion wear and abrasive wear and they become boundary friction under oil lubricated condition.

Study on Friction and Wear Behavior of Glass Fiber and Fly Ash Reinforced MC Nylon Composites

The glass fiber and fly ash reinforced monomer casting nylon composites (coded as GFFAPA) have been prepared by anionic polymerization of caprolactam. The friction and wear behaviors of composites with different proportion of glass fiber and fly ash under dry condition and water lubrication were investigated through a ring-black wear tester. The worn surfaces were observed and analyzed using a scanning electron microscope and a surface profilometer. The results show that the tribological properties of composites were significantly affected by the proportion of glass fiber and fly ash. GFFAPA composites had lower friction coefficients and better wear resistance than MC nylon. The higher wear resistance of the composite could be attained with the proportion of glass fiber 30% and fly ash 10%, which respectively decreased 57.8% and 89.9%. The main wear mechanism of composites with low proportion of glass fiber and fly ash were adhesive and abrasive wear while that of composites with high proportion of glass fiber and fly ash were abrasive and fatigue wear. Compared with dry friction, the friction coefficient and wear rate of composites Sg3+f1 respectively decreased 42.5% and 77.8% under oil lubricant, while the wear rate was bigger under water lubrication than that with no lubricant. The wear mechanism under water or oil lubricated condition was principally abrasive wear.