Study on the Ageing Process of the 6xxx Series Aluminum Alloy Wires for Overhead Conductors

The 6xxx series aluminium alloy wires (with the diameters of 2.84 mm) produced by the continuous drawing and rotary-wheel continuous casting, were directly aged in different conditions. The results show that, when ageing temperature is at 150°C, the tensile strength of the wire firstly decreased from 283 MPa to 265 MPa as the ageing time extended from 0 to 4 hours, and then increased from 265 MPa to 270 MPa as the ageing time extended from 4 to 12 hours, and finally decreased from 270 MPa 263 MPa as the ageing time extended from 12 to 24 hours. The electrical resistively of the wires continued decreases with the ageing time extend from 0 to 24 hours. When the ageing temperature is at 160, 170, 180 and 190 °C, both the tensile strength and the electrical resistively of the wire continuously decreased with the ageing time extended from 0 to 24 hours. When the ageing time was identical, the wires with higher ageing temperature possessed lower tensile strength and electrical resistively.