Efficient wear resistance at the steel/steel friction interface achieved through Span65 confined PAO10 gel lubricant

Ultra-low wear technology provides an effective solution to prolong the service life of mechanical equipment. However, there are still significant challenges in achieving ultra-low wear at the steel/steel interface over long periods. In this work, a PAO10-SPAN65 composite semisolid lubricant (PAO10/SP65) was designed with sorbitan tristearate (SPAN65) and base oil poly α-olefin 10 (PAO10). The wear rate of the steel lubricated with PAO10/SP65 (1.31×10⁻⁸ mm³·N⁻¹·m⁻¹) was 96% lower than that of PAO10 (3.52×10⁻⁷ mm³·N⁻¹·m⁻¹). In addition, after 10 h of friction testing at a contact pressure of 0.82 GPa, the wear of the steel surface is still close to zero, with a wear rate of 4.13×10⁻⁹ mm³·N⁻¹·m⁻¹. This study provides a new design idea for realizing ultra-low wear of engineering steel.