Thanks to all who responded!
ZraHamilton gets this one correct by answering all four items and giving an explanation.
The only thing I would add is this:
In Boundary Lubrication a very thin film of lubricant exists but not enough to separate the asperities. The load will be carried by the
asperities alone
unless there is an Anti-Wear (engines and transmissions) or an Extreme Pressure (Hypoid differential type loads) with a metallo-chemical interface between the sliding or rotating parts.
In Mixed Lubrication you have both a hydrodynamic and boundary lubrication situation where the thin film AND the asperities are carrying the load
unless t[/b]here is an Anti-Wear (engines and transmissions) or there is an or an Extreme Pressure (Hypoid differential type loads) with a metallo-chemical interface between the sliding or rotating parts.
The best case of course would be Hydrodynamic Lubrication.
The virtual BITOG Cup with the
emblem and the XWXX Synthetic Oil goes to ZraHamilton .