Tribofilms Produced by Supply of Fine Metal Particles in Vacuum

Abstract

This study demonstrates wear-protective tribofilms produced by an artificial supply of fine metal particles onto rubbing steel surfaces in vacuum. The supplied metal particles were Ag, Bi, Cu, Ni, Ti, and Fe, with the diameters of the particles ranging from 20 nm to 45 μm. The influence of the metal type of the supplied particles on the behavior of tribofilm formation as well as wear of the tribofilms were investigated. When Bi or Ti particles were supplied, the rubbed surfaces were almost entirely covered with the tribofilm. The thickness of the tribofilm produced by supplying Bi particles was 5 ∼ 8 μm. The tribofilms formed by supplying Ag, Bi or Cu particles showed initial low wear in wear tests, and the sliding distance of initial low wear was longer for the tribofilms formed by supplying finer particles. The tribofilms produced by supplying Bi (1.5 μm) particles showed the longest sliding distance of initial low wear.

Keywords

• tribofilm
• fine metal particles
• wear
• pin-on-disc
• bismuth