Liquid Metal on Copper-Coated Heatsink?

[cjd2002]

Hi,

 

I am planning on repasting my laptop with Thermal Grizzly Conductonaut.   I know that liquid metal can't be used with aluminum heatsinks because the gallium will react with the aluminum and damage the heatsink.  So, my question is, does it matter if there is aluminum under the surface where the liquid metal is applied?  (I am awaiting a reply from my laptop manufacturer to confirm this) My laptop's heatsink is made of copper-coated aluminum (I think it's aluminum, could be something else like nickel).  Would applying the Conductonaut be safe, since it would be applied on the copper?  Or should I refrain from using liquid metal due to the presence of aluminum in layers under the surface of the heatsink?

 

Thanks to anyone who can lead me in the right direction!

Chris

[Tabs]

10 minutes ago, cjd2002 said:

Hi,

 

I am planning on repasting my laptop with Thermal Grizzly Conductonaut.   I know that liquid metal can't be used with aluminum heatsinks because the gallium will react with the aluminum and damage the heatsink.  So, my question is, does it matter if there is aluminum under the surface where the liquid metal is applied?  (I am awaiting a reply from my laptop manufacturer to confirm this) My laptop's heatsink is made of copper-coated aluminum (I think it's aluminum, could be something else like nickel).  Would applying the Conductonaut be safe, since it would be applied on the copper?  Or should I refrain from using liquid metal due to the presence of aluminum in layers under the surface of the heatsink?

 

Thanks to anyone who can lead me in the right direction!

Chris

I very much doubt that the heatsink would be aluminium coated with copper, aluminium doesn't like to bond in that fashion. I would wait for their response, you may find that the baseplate is fully copper, and it's simply welded to aluminium blocks for thermal dissipation purposes.

 

The main reason for this (other than cost; copper is more expensive than aluminium) is that Copper conducts heat more easily than aluminium, but it radiates it slightly less efficiently. Using Aluminium as the radiator and Copper for the base is a good middle ground between the two.

 

If it turns out that it *is* some kind of coating on aluminium, I wouldn't risk the liquid metal. Any imperfections, scratches or defects in the plate could allow the gallium compounds to erode the aluminium - it would be just as bad as putting it straight on an aluminium plate.