Abstract: A thermomechanical method for forging a precipitation-hardenable aluminum alloy workpiece comprises the steps of: (1) solution heat treating the workpiece to achieve a substantially homnogeneous supersaturated solid solution of the alloy throughout the workpiece; (2) partially aging the workpiece at a temperature sufficient to cause second-phase precipitate particles to form in the workpiece, the aging of the workpiece continuing until the precipitate particles acquire a size sufficient to restrict dislocation movement in the workpiece during subsequent forging without substantially hindering workability of the alloy; and (3) mechanically working the workpiece isothermally at the temperature at which aging of the workpiece occurred.