During the lubricating process, there is a common understanding, the lubricant will be subjected to three different phases, starting with Hydrodynamic, Mixed and Boundary lubrication. During the phase transition between hydrodynamic and mixed lubrication, is often refered as Elasto Hydrodynamic Lubrication (EHL).
Anti-Wear and Extreme Pressure additives operate mainly in the boundary lubrication phase, where metal–to–metal contact is observed, with majority of the lubricant squeezed out of the contact zone, resulting in a tribochemical reaction of the Anti-Wear and Extreme Pressure additives on the metal surface.
A clear distinction between Anti-Wear and Extreme Pressure additives are not always so clear due to the various types of chemistries used in differing applications. However, Anti-Wear additives generally deposit chemical layers on the metal surface during normal operating conditions. Extreme pressure additives on the other hand become active when the system comes under serve stress, to prevent the welding of moving parts.
For this specific application area Italmatch continue to successfully market the Dapraphos product series.