do copper heatsinks lose conductivity over time?

I was wondering this because every gpu heatsink I've ever had, over time and use, turns a brownish green. Perhaps some kind of oxidation? it only happens to the gpu so i assume it has to do with heat.

Anyway, if you know what I'm talking about, does this result in poorer cooling? I can't help but feel my temps went up since my heatsinks been turning darker. Could be mental though, don't really know =p

( i ask because I'm about to order a a few things from the asus estore and wondering if i should get a new copper heatsink block while im at. im doing a "copper" mod and before i add the copper blocks i want the heatsink at good performance)

 

Yes the brownish green color or bluish tinge is oxidation as a result from copper reacting with oxygen. This is probably just what you said "mental", as the density of copper or the molecule structure would never change in a laptop environment, the heat you are experiencing probably is related to the heatsink, but not the copper itself, probably just dust may be building up on the heatsink fan. Might want to carefully take it out and blow it out with an air compressor (be very careful) or a more safe decision would be to buy some "canned compressed air" at a local Staples or other store that carries computer maintenance items. Some heatsinks do have thermal pads or compound/paste on them to help transfer heat, so you might want to look at it, scrape the old stuff off (if any) and carefully apply some fresh stuff. The oxidation more so in the GPU area, would just mean that that area has more airflow exposure, speeding the process of oxidation. It shouldn't alter the thermal properties of copper.

Edit:copper is expensive at the moment, and i'd hate to see you buy a big ole' block of copper that is identical to your original heatsink, for no reason, also the heatsink fan may be starting to go, but give blowing any dust out first before you get into fan replacements.

 

thanks for your reply, rep added. What about having an effect on the "copper blocks" i plan on attaching to it (for more heat-spread). They're basically ram coolers I'll be applying with a thermal tape. Forge has a thread around here on it and I plan on doing the same =)

 

It may have a miniscule effect on heat transfer and that's if you attach the copper blocks to the area's with oxidation itself, and even then the difference would be tenths of a Watt of thermal dissipation, nothing to worry about. I saw a mod for a ThinkPad T43 for the wireless card area (underneath touchpad) similar to what you were planning on doing. It worked apparently and the guy used alot of thermal compound. Basically, consider heatsinks like circuits sort of, any place you want heat to go to, connect it with thermal compound or make direct contact with a thermally conductive material i.e copper, and protet heat sensitive components with thermal compound.