Modification of AA-6201 alloy for manufacturing of high conductivity and extra high conductivity wires with property of high tensile stress after artificial aging heat treatment for all-aluminium alloy conductors

In this paper, a modification method to manufacture high conductivity (HQ and extra high conductivity (EHC) wires with high strength properties from AA-6201 redraw rod has been presented. In the experiments, redraw rod has been produced using an extrusion press. In conventional heat treatment processing of HC and EHC wires produced from unmodified AA-6201 alloy, the wires should be exposed to artificial aging at 175 degrees C with soaking time higher than 6 It or at 195 degrees C/4 h to have conductivity above nominal value 52.5-53%IACS. Thus, wires gain high conductivity but decrease their tensile stress due to incoherence precipitation. However, this negative effect on the tensile stress can be prevented by the method explained in this study. This is inoculation of molten AA-6201 alloy in tundish with 3% AlB2 compound in 9.5-mm rod form to decrease detrimental effect of Ti, Cr, Zr and V on the conductivity. Thus the wires produced from modified alloy do not need treatment time higher than 6 h at 175 degrees C to reach high and extra high conductivity. So, the alloy wires have got rid of exposing excessive aging and keep their tensile stresses at maximum level due to treatment at low temperature. Inoculation principles of the molten metal and homogenisation parameters that affect properties of HC and EHC wires were explained in details. Using modified AA-6201 wires AAAC conductor with extreme conductivity and also tensile stress was manufactured. Results from measurements of tensile and conductivity of HC and EHC wires taken from conductor samples have been tabulated to show effects of AlB2. (C) 2005 Elsevier Ltd. All rights reserved.