When does boundary lubrication occur?
A) When distances between metal surfaces are wider.
B) Only between two dissimilar metal surfaces.
C) When distances between metal surfaces are narrow.
D) When the primary function of the lubrication is cooling.

Question

Quizplus · Accepted Answer

Boundary lubrication occurs when distances between metal surfaces are narrow, which means that the lubricating film is not thick enough to separate the surfaces completely. This can happen when the load is high or when the speed is low. In such cases, the lubricating film may break down, and the surfaces can come into direct contact, causing wear and friction.

When Does Boundary Lubrication Occur