There are many kinds of solid lubricant, flake graphite is one of them, is also in powder metallurgy friction reduction materials in the first to add a solid lubricant. Flake graphite has a layered lattice structure, and the layered failure of graphite crystal is easy to occur under the action of tangential friction force. This ensures that flake graphite as a lubricant has a low coefficient of friction, typically 0.05 to 0.19. In vacuum, the friction coefficient of flake graphite decreases with increasing temperature from room temperature to the starting temperature of its sublimation. Therefore, flake graphite is an ideal solid lubricant at high temperature.
The chemical stability of flake graphite is high, it has strong molecular binding force with metal, forming a layer of lubrication film on the metal surface, effectively protecting the crystal structure, and forming flake graphite and graphite friction conditions.
These excellent properties of flake graphite as a lubricant make it widely used in materials of different composition. But USING FLAKE graphite as a solid lubricant also has its own shortcomings, mainly in vacuum flake graphite friction coefficient is twice that of air, wear can be up to hundreds of times, that is, the self-lubrication of flake graphite is greatly affected by atmosphere. Moreover, the wear resistance of flake graphite itself is not enough, so it must be combined with the metal matrix to form metal/graphite solid self-lubricating material.
Post time: Aug-22-2022