Friction increase on Aluminium/Steel interface due to water

[Robski]

G'day all,

My question is simple:

We have a situation where steel is sliding across aluminium. When the "system" is dry the steel slides reasonabley well across the aluminium, but once the system is wet the friction appears to increase and the steel won't slide across the aluminium.

Is there any information available about the effect of water on aluminium, and would there be a better interface available for wet conditions. The only limiting factor is that the Aluminium must remain but the steel is interchangeable.

Regards

Rob

 

[arunmrao]

The possibility of rust layer on steel increasing the friction between two surfaces exists. Please look around for rust stains and have them cleaned. Alternately you could use some rust inhibitors in the wet medium.

 

[waqahmad]

are u using any kind of lubricant!
find a siutable lubriocant which works best between steel and aluminium!
in the presence of lubricant layer inbetween the steel and aluminium, u wont have the problem of wet or dry conditions.

waqahmad

 

[Robski]

Thanks Gents.

Lubricant is not an option as the aluminium is a material that we handle and cannot get dirty for various reasons. I was more interested if anyone knew if the friction between these metals was likely to increase due to water?

 

[sciguyjim]

Besides causing rust to form on the steel, the water could be causing slight corrosion of the aluminum too. Aluminum is quite a reactive metal and can dissolve in acidic, alkaline, and even neutral water. There may also be electrochemical corrosion if the steel/water/aluminum assy is acting like a battery. Since you can't lubricate the Al, can you maybe passivate it with an oxide or nitride layer?

 

[gdodd]

Try anodizing your aluminium and using stainless steel instead of your current material. Both steel and aluminium if unprotected will gradually corrode when exposed to H2O.