Copper vs aluminium

[ebysamz]

Im planning a custom loop under a very low budget for cooling a 4790k. I can't find any copper radiators or aluminium water blocks out there so I'm stuck with aluminium rads and copper water blocks. Can anyone explain exactly why mixed metals is a bad idea? Can anyone tell me where I can find copper rads or aluminium water blocks? I can only buy from AliExpress, Banggood or Amazon as a last resort. How much radiator real estate would I need if the ambient temps in my room are around 30 Celsius?

[Drak3]

Aluminum wears down (relatively) quickly, whereas copper is very resistant to wear if it is the only metal in the loop. If Copper is paired with aluminum, however, the aluminum particles in the water will wear down the copper. There are some compatible metals that mitigate this effect somewhat, as well as kill-coils and anti-corrosive additives.

 

I'd suggest a 240mm rad at the least.

[Sakkura]

10 minutes ago, Drak3 said:

Aluminum wears down (relatively) quickly, whereas copper is very resistant to wear if it is the only metal in the loop. If Copper is paired with aluminum, however, the aluminum particles in the water will wear down the copper. There are some compatible metals that mitigate this effect somewhat, as well as kill-coils and anti-corrosive additives.

 

I'd suggest a 240mm rad at the least.

Copper is more noble than aluminium, so there will be galvanic corrosion of the aluminium. Though I suppose there could also be physical damage (abrasion) to the copper.

[ebysamz]

Do you guys know where I can get copper radiators? All the radiators I can find are aluminium. And don't the metals have to be connected by a conductor for galvanic corrosion?

[W-L]

14 hours ago, ebysamz said:

Do you guys know where I can get copper radiators? All the radiators I can find are aluminium. And don't the metals have to be connected by a conductor for galvanic corrosion?

They only need to be in contact or through the fluid for metal ions to potentially cause galvanic corrosion, any good quality watercooling radiator will be full copper or copper and brass. Personally I would recommend to get a kit and go with a proper loop.