SEM images showing the morphologies of worn surfaces after sliding for 20 min at different sliding speeds with applied load of 40 N

Nanostructured materials have attracted increasing attention due to their greater wear resistance and special tribological behavior in comparison with their coarse-grained counterparts. The wear performance of nanostructured materials appears to be extremely sensitive to the environment in which sliding occurs. As is well known, oil lubrication is the first choice for machines in most cases. However, in the food and pharmaceutical industries, oil lubrication is not a good choice, as leakage of lubrication oil would lead to contamination and create a possible fire risk; therefore, it is important to study tribological properties of bulk nanostructured materials under clean water lubrication.

Researchers of the State Key Laboratory of Solid Lubrication have investigated the tribological properties of nano-eutectic Fe1.87 C0.13 alloy under a water lubrication environment, and compare them with those of coarse-grained Fe1.87 C0.13 alloy. They also explore the corresponding friction and wear mechanisms.

It is found that The wear rates of both alloys increase with increasing applied load. The wear rate of the nano-eutectic Fe1.87 C0.13 alloy does not change significantly with increasing sliding speed, whereas that of the coarse grained Fe1.87 C0.13 alloy initially decreases and then increases. The nano-eutectic Fe1.87C0.13 alloy shows lower wear resistance at low applied load but greater wear resistance at high applied load than the annealed coarse-grained Fe1.87C0.13 alloy. The friction coefficients of both alloys decrease slightly with increasing applied load but increase appreciably  with increasing sliding speed. The friction coefficient of the nano-eutectic Fe1.87C0.13 alloy is slight higher than that of the annealed coarse-grained Fe1.87C0.13 alloy. With increasing applied load, the wear mechanism of the nano-eutectic Fe1.87C0.13 alloy is transformed from plowing and corrosion wear to slight fatigue cracking, whereas that of the annealed coarse-grained Fe1.87C0.13 alloy is transformed from plowing and corrosion wear to severe fatigue flaking.

The work has received support from the National Natural Science Foundation of China, the National Program on Key Basic Research Project (973 Program), and the Innovation Group Foundation from Natural Science Foundation of China.

Its detailed report was published in Tribol. Lett. (Tribol. Lett. (2010) 40:105–111).

Abstract of the paper published in Tribol Lett