The application of an external de electric field E = 5 kV/cm during the solution heat treatment (SHT) of AA6022 at 475-552degreesC increased the as-quenched resistivity. An increase continued throughout subsequent natural aging, and there occurred an increase in the tensile properties for the T4 temper. The increase in yield and tensile strength produced by the electric field applied during the SHT is equivalent to a reduction of 10-25degreesC in the SHT temperature. A thermodynamic analysis of the results indicated that the field reduced both the enthalpy DeltaH(s) and entropy DeltaS(s) of solution, giving a reduction in Gibbs free energy DeltaG(s), and in turn an increase in solubility of the alloying constituents. (C) 2004 Kluwer Academic Publishers.