The invention relates to a method of manufacturing an Al or alloy workpiece, comprising the steps of (a) providing an AlAl alloy workpiece, (b) pre-treating of the outersurface of the Al or Al alloy workpiece, and (c) plating a metal layer comprising nickel onto said outersurface of the pre-treated Al or Al alloy workpiece, and wherein during step (c) said metal layer comprising nickel is deposited by electroplating both nickel and bismuth using an aqueous bath comprising a nickel-ion concentration in a range of 10 to 100 g/l and a bismuthion concentration in the range of 0.01 to 10 g/l. The invention further relates to an aqueous plating bath for use in the method of this invention.