Components used in water, lubricated or submersed environments, face considerable tribological challenges that can ultimately affect performance and reduce the life of the larger system particularly those that come in contact or slide against other parts. This process includes pump parts, mechanical seals and high-pressure valves manufactured often using ceramic substrates designed to survive wet, corrosive environments. Unfortunately, these substrates are also easily damaged due to high friction of sliding/mated parts due to a consistently high COF when uncoated.
With that in mind, the goal is to keep the coefficient of friction of sliding parts as close to zero as possible. The COF is the measure of the amount of friction existing between two surfaces. A low value of COF indicates that the force required for sliding to occur is less than the force required when the COF is high. Typical values for the COF when sliding is occurring between polished oiled metal surfaces, for example, is 0.1.