Temperature dependance friction coefficient

[dm3415]

Does anyone have any data or general knowledge of the effects of temperature on the friction coefficient of metals? In particular steel on oil-impregnated brass? Thanks for your help!

 

[tbuelna]

dm3415,

Here's some very general knowledge:

I don't believe that temperature (as long as the temperatures are not extreme) will have much effect on a dry metal-to-metal interface friction. But temperature will affect any lubricant film present, especially a liquid like your oil. Higher temperatures in general will decrease oil viscosity and should produce lower frictions in most contacts regimes (hydrodynamic, mixed or boundary).

Besides friction, temperatures most definitely will have an effect on the surface fatigue strength of your shaft/bearing materials.

Most lubricants also have flash temperature limits. If there is sufficient local heating at the contact zone to flash off the lubricant, you will immediately have un-lubricated metal-to-metal contact and the friction (plus the heat it generates) will immediately jump up, compounding the problem.

Hope that was helpful.
Terry