The effect of serpentine additive on energy-saving and auto-reconditioning surface layer formation

Abstract

Purpose This paper aims to investigate the energy-saving effect and mechanism of serpentine as lubricant additive in the simulated condition. Design/methodology/approach An ABLT-1 bearing test machine was used for 1,350 hours and an MM-W1 three-pin-on-disk apparatus was used to investigate its anti-friction effect. The worn surface was characterized by scanning electron microscopy equipped with energy dispersive spectroscopy. Findings The results show that the energy-saving effect was improved after adding serpentine powder in oil and that both the friction coefficient and mass loss were dramatically decreased. The analysis on worn surface layer demonstrates that an auto-reconditioning surface layer was formed on the worn surface, which was responsible for the decrease in friction and wear. Originality/value The simulation test for the metal bearing was conducted over 1,350 hours using lubricant with and without serpentine powder. The addition of serpentine powder enhanced the energy-saving rate over time, stabilizing at about 13 per cent after 1,000 hours. An auto-reconditioning surface layer was formed on the surfaces of disassembled bearing lubricated with serpentine doped oil, resulting in dramatic decrease of both the friction coefficient and the mass loss. In addition to normal load and the accumulation of serpentine powder in the furrows and scratches of the deformed layer, the formation of the surface layer was possibly related to the substrate deformation induced by friction force.