Remarkable lubricity of CNTs microspheres as additives in oil lubricant for ceramic components

Severe wear was often caused by adhesive wear and tribo-chemical reaction for ceramic components. In view of this situation, potentials of carbon nanotubes (CNTs) used as oil additives were explored for lubrication of ceramic/steel tribo-components. Microscopic morphology and dispersion stability of the prepared CNTs were characterized. CNTs microspheres were formed and this might because of their aggregation that also lead to the weak dispersion stability. Additionally, nano-fluids containing various concentration of CNTs microspheres were prepared for exploring the optimum concentration, where their lubricating behavior for ceramic/steel tribo-components was investigated to determine the relation between CNTs microspheres and tribological properties. The results indicated that the optimum concentration was 0.2 wt%, where 53.1 % of friction reduction and 50.7 % of wear resistance were achieved at high contact stress of 1.35 GPa. The superior lubricity of CNTs microspheres might be attributed to their rolling movement and formation of protective film.