the state of lubrication when conditions exist that do not permit the formation of a lubricant film capable of completely separating the moving parts. Under these conditions, additives are used to increase oil film strength or coat metal surfaces with a sacrificial 'anti-wear' film. Anti-wear additives are commonly used in more severe boundary lubrication applications. The more severe cases of boundary lubrication are defined as extreme pressure conditions; they are managed with lubricants containing EP additives that prevent sliding surfaces from fusing together at high local temperatures and pressures.
A lubrication condition at friction positions under boundary friction. Friction bodies are coated with a thin lubricant film. There is a high contact of surface roughness and wear is unacceptably high.
Lubrication condition in friction sites under boundary friction; friction bodies coated with thin lubricant film; intensive contact of surface roughness; unacceptably high wear.