[SOLVED] Why do AIO watercoolers mix aluminium and copper?

[Lukeonuke]

Ive noticed that literaly every AIO water coller has a aluminium radiator and a copper block, but basic knowledge of water colling tells thats a bad idea. Why do manufactures use them when they know that soot will apear on the block or in the radiator

 

[EndEffeKt_24]

Ive noticed that literaly every AIO water coller has a aluminium radiator and a copper block, but basic knowledge of water colling tells thats a bad idea. Why do manufactures use them when they know that soot will apear on the block or in the radiator

The copper block is more important for heat transfer. The aluminium saves costs. Its that easy.