Oil Evaporation from Aluminium Surface.

[triumphv8]

Hi,

We are a user of stamped metal parts. The parts must be supplied clean with no wet oil residues, so an evaporating oil is used.

On steel parts we have no probems, the oil evaporates within minutes in ambient condiitons as the part travels down a conveyor to be packed by our supplier.

However we have recently started using an Auminium part and the same oil does not fully evaporate - even after a week.

Our supplier states the reason as the oil becoming 'embedded' in the Aluminium surface but can not explain this further. Please can anyone explain the mechanism that is causing this on the Aluminium part ?

Thanks Chris

 

[Robertmet]

What's the surface condition of the aluminum ? Oxides can be porous and hold oil.Can it be some reaction between oil and aluminum ?

 

[Ron]

Is there a chance that the flash point of the lubricant is too high for your application? Aluminum tends to stay cool in a shop environment. If you have a thermal requirement for your evaporation, you might not be seeing that with the aluminum.

Extruded aluminum can also have an "open grain" condition. Would require reasonably sophisticated analysis to determine grain embedment by oil, though.

 

[IRstuff]

Pursuant to Ron's questions, have you tried to evaporate the oil with different temp/time combinations? Aluminum thermal conductivity is 3 to 4 times that of steel.

TTFN

FAQ731-376