Why does the water head use copper instead of aluminum?
Play cold water friends know, whether it is cold head CPU or video card, are used in the copper material.The heat conductivity of aluminum, which is commonly used for heat dissipation, is also good, so why not use aluminum as a cold head?
Cold head is the chip, heat transfer heat absorption, the material used to have a high thermal conductivity. So with that said, let’s talk a little bit about what thermal conductivity is.
The thermal conductivity coefficient refers to the heat transfer through an area of 1 square meter (watt/meter · degree) in 1 second (1s) under stable heat transfer conditions. The temperature difference between the two sides of a material 1m thick is 1 degree (K, ℃).
The general idea is how fast something transfers heat. Take, for example, holding a stone in hot water, your fingers can barely feel the temperature change. If you touch hot water with an iron rod, your fingers will soon feel the temperature change. This is actually the reason for the different thermal conductivity.
In real life, materials with low thermal conductivity are used as insulation materials, such as asbestos and perlite, which are applied because of their slow heat transfer characteristics. Electronic chip heating requires the rapid release of heat, which requires materials with high thermal conductivity, and metal is the preferred material.The thermal conductivity of copper is 377, that of aluminum is 237, and that of silver is 412. Silver is too expensive to be used as a cold head, so by contrast, copper is the best choice.
Then someone said, in the water - cooled computer heat sink row has the aluminum cold row!In fact, this is related to the specific heat capacity, which is the heat required to increase the temperature of a substance per unit mass by 1 degree, copper is 0.39J/kgK, aluminum is 0.9 J/kgK, so the heat emitted by reducing 1 degree of copper is smaller than that of aluminum, that is, copper should dissipate heat faster than aluminum, so why use aluminum?
It turns out that tin is needed for the welding of the channel with cold discharge of copper, and the specific heat capacity of tin is very large, which restricts the heat dissipation speed of copper, while the density of aluminum is obviously lower than that of copper. For the same type of cold discharge, aluminum is thinner and lighter, making it easier to use. So technically speaking, there is not much difference between copper and aluminum.