Mechanical and Conductive Performance of Aged 6xxx Aluminum Alloy during Rotary Swaging

Thermomechanical treatment consisting of heat treatment and deformation is an effective processing route for precipitation-hardened 6xxx alloy (Al-Mg-Si-Cu system), and precipitates and dislocations produced during the process can significantly change its mechanical and conductive performance. We therefore investigated the microstructural evolution of precipitates in a representative 6xxx alloy during thermomechanical treatment. When the precipitates encountered the accumulated dislocations, the precipitates were bent and broken into dispersed smaller particles. The strength of the alloy was significantly improved by the proliferation of dislocations and precipitates and desired electrical conductivity was obtained as well. Our results prove that peak aging plus cold rotary swaging is an efficient processing route for simultaneously improving the mechanical and conductive performance of 6xxx alloy.