Galvanic Corrosion in Cooling Circuit - Does This Logic Make Sense?

[jrootatendurance]

Im designing a system that has copper mirrors mounted within an aluminum housing. The copper mirrors will require water cooling, and the water is delivered through jackets in the aluminum housing.

From a heat transfer perspective, it would be ideal if the water came in contact with the backside faces of the copper mirrors. My concern in this scenario is from the corrosion perspective, now the copper and aluminum are both part of the same cooling circuit.

I recently had a discussion with another engineer about this concern and was given the suggestion of using a third material - a stainless steel piece - that will live in the space between the copper mirror and the aluminum housing. The coolant will come in contact with all 3 materials. In this case, the copper is no longer in physical contact with the aluminum, but they are both still in contact with the same coolant, as is the stainless steel.

The question that I am asking for now is - Does adding the stainless steel mount plate to the system as a layer between the copper and aluminum help the corrosion problem at all?

The only electro-potential in this system is the inherent potential in the materials, this is not an electrical system. As for the coolant, it is TBD and is yet to be specified.
Thanks for any insights.
Jeff

 

[Compositepro]

The stainless steel will not really help. It will increase the distance between the two and increase circuit resistance, which will have minor effects.
Plate the backside of the copper, that is in contact with water, with aluminum.

 

[EdStainless]

If this was a piping system you could use a length of SS to separate the two other materials.
The idea of plating is a good one.
Be careful about what you use for a sealant. If this is getting very hot you will need a material that will withstand hot water. Must rubbers will not.

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Plymouth Tube

 

[moltenmetal]

A stainless steel intermediate piece will reduce the corrosion rate but not eliminate the corrosion.

If the coolant can be a coolant mixture with corrosion inhibitors as well as being closed loop and deoxygenated, rather than being "water", then the stainless piece isn't really needed.

 

[EdStainless]

There are good inhibitor packages available for mixed metallurgy systems (think automotive).
And excluding all air from the system is a major requirement.


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Plymouth Tube

 

[jrootatendurance]

Thanks all for the information.