Tribological study of iron infused carbon tubes additive in gearbox, engine, and vegetable-based lubricants

Tribo-film strength in the boundary layer regime depends predominantly on the type of additives present in lubricant. Here, we have synthesized iron-infused carbon tubes (Fe-CTs) that can be used as an additive to improve the tribo-film strength of the lubricants (gearbox, engine, and vegetable oil) under the boundary layer regime. Additive synthesis was done by adopting the thermal decomposition of carbon and iron precursors at 800 °C in inert atmosphere. Small amount of additive insertion into the lubricant are found to reduce the coefficient of friction of the lubricant by maximum ∼54% for gearbox oil and ∼22%, ∼15% for vegetable and engine oils respectively. Reduction in friction showed direct relation with the scar diameter and depth profiles. Tribo-surface analysis revealed, the Fe-CTs formulated lubricants provide strength to the tribo-film and protect the surface from severe damage by filling the asperities.