Re: Coollaboratory Liquid Metal

pbi,

Sorry to reply so long after your posting; however, you or other readers may still benefit from this.

It is unlikely that the integrated heat spreaders (IHSs) atop most Intel or AMD processors are aluminum. The AMD64 processors (including Opterons) have copper IHSs, despite appearing silvery. Current Intel processors probably use either copper or a copper alloy as well (please verify this with Intel prior to experimenting with gallium and aluminum!)

Even though most IHSs are of copper or copper alloys, be aware that gallium attacks copper too, though much more slowly than it attacks aluminum.

Perhaps "gallium attack" is overly pejorative: the gallium is actually alloying with the adjoining metal. The result can be a mess, or exactly what you intended, depending on the alloy metal and how much gallium was used.

Thus, gallium materials CAN be useful in formulating thermal paste, EVEN if the paste is used to join aluminum heatsinks to aluminum IHSs. Gallium (or gallium alloys) will "cold weld" two aluminum parts together. Of course, you need to know exactly what you're doing, use the gallium material very sparingly, and be looking for a PERMANENT bond. But note, such a bond will be nearly optimal from a heat transfer standpoint!

Ya gotta break some eggs if you want to make an omelette.