Effects of natural aging and pre-aging on the strength and electrical conductivity in Al-Mg-Si AA6201 conductor alloys

The effects of natural aging (NA), and its combination with pre-aging (PA), on the strength and electrical conductivity (EC) of drawn Al–Mg–Si AA6201 conductor alloys were studied. Natural aging had a negative impact on precipitation before the drawing process. However, wire drawing counteracted the detrimental influence of natural aging on precipitation hardening; after drawing and post-aging, the NA samples exhibited a better combination of strength and EC compared to those of the samples that did not undergo NA. Transmission electron microscopy results show that the NA samples exhibited a higher number density of precipitates in the drawn and post-aged conditions relative to those of the samples that did not undergo NA. The combination of natural aging and pre-aging followed by wire drawing and post-aging provided the highest strength (369 MPa) with an acceptable EC (53% IACS). The applied natural aging and pre-aging modified the strengthening contributions in AA6201 conductor alloys in favor of precipitation hardening. The relationship between strength and EC was analyzed in detail using strengthening models and Matthiessen's rule based on various microstructural features.