Thermomechanical ageing of copper-clad aluminum wires submitted to creep test conditions

摘要

Creep tests were performed on copper-clad aluminum wires at 423 K and different stresses to cover potential operating load ranges in automotive industry. The lifetime of the wires is strongly dependent on the existence of an initial heat treatment and on the applied stress. It can be correlated with the formation of the three intermetallics Al_2Cu, AlCu and Al_4Cu_9 identified by TEM diffraction. All results are discussed to understand mechanisms that could lead to the embrittlement of copper-clad aluminum wires by creep.