Deformation behaviour of cryo-drawn CuAl-wires

The effect of temperature on the active deformation mechanism is studied. For this purpose cryogenic drawing of several CuAl alloys was performed. Hence, a solid lubrification is needed which remains operating at cryogenic temperatures. We present a comparison of several solid lubricants for the deformation of two Copper alloys. The comparison cryogenic temperature deformation of several CuAl alloys with conventionally drawn wires shows that the strengthening of these alloys during the deformation process is significantly affected by their stacking fault energy. The deformation at cryogenic temperature is most effective at intermediate stacking fault energies. This is interpreted in terms of a changing deformation mechanism from dislocation slip to deformation twinning. The analysis of the microstructure during the deformation process strengthens these assumptions.