Tribological behavior of nanocrystalline Fe88Si12 alloy in vacuum environment

• The wear resistance of nanocrystalline alloy improves more effective in vacuum.
• The tribo-oxidation could mask the effect of hardness of alloys.
• The adhesion and oxidation of nanocrystalline alloy have been restricted in vacuum.

The tribological behavior of nanocrystalline Fe88Si12 alloy in vacuum environment has been investigated compared with coarse grained counterpart. The results demonstrated that the friction coefficient of the Fe88Si12 alloy reduced with the decrease of both grain size and oxygen partial pressure. The wear resistance of the Fe88Si12 alloy improved more effective in vacuum than in air as the grain size decreased. As the hardness and oxidation activity of the Fe88Si12 alloy decreased, the wear mechanism changed from adhesion and oxidation to plastic deformation and adhesion when the grain size and oxygen partial pressure decreased.