2021-03-23 The most common heat sink materials are aluminium alloys. Aluminium alloy 1050A has one of the higher thermal conductivity values at 229 W/m•K but is mechanically soft. Aluminium alloys 6060 and 6063 are commonly used, with thermal conductivity values of 166 and 201 W/m•K, respectively. The values depend on the temper of the alloy. Copper has around twice the conductivity of aluminium, but is three times as dense and, depending on the market, around four to six times more expensive than aluminium. Aluminium can be extruded, but copper can not. Copper heat sinks are machined and skived. Copper is still the best material with highest conductivity for high performance applications.