Friction

[gerkin]

Why does the friction coefficient signifcantly increase for steel to steel contact in an inert gas such as helium

[jake-the-peg]

I didn't know it did!

I guess that when two steel plates rub together in air any exposed metal will rapidly form a certain amount of oxide coating which will not happen in Helium.

I'd imagine that the frictional coefficient for iron oxide is higher than for pure metal.