Increasing thermal conductivity in aluminium-copper compound castings: Modelling and experiments
Hans Jürgen Maier, Richard Gawlytta, Andreas Fromm, Christian Klose
Abstract
Compound cast heat sinks have various advantages over conventionally manufactured ones, but oxides present on the metals and formation of a brittle intermetallic layer (IMC) make casting difficult. In the present study, a novel approach was used that employs a silane-doped argon environment to overcome these issues. Oxidation could be fully suppressed and thermal heat conductivities around 67 W/(m·K) were obtained for the compound zone. The microstructural analysis revealed that the thickness of the IMC layer could be kept below the critical value of 3 µm. Yet, the process window was found to be extremely tight. The modelling revealed that the critical time period for formation of the IMC layer is only on the order of a few 10 s.