Abstract: A zinc alloy, having a copper layer coated thereon, consists essentially of from about 0.1 to about 0.8 weight percent copper, about 0.01 or more weight percent aluminum; up to about 0.05 weight percent magnesium, the balance being essentially zinc. The copper coated zinc alloy is advantageously employed to produce various cast, extruded, molded articles and the like including trim, fixtures as well as coin blanks. Further, the present invention relates to a metal article comprising a zinc base alloy having a copper overlayer in direct contact with the zinc base alloy, said alloy comprising about 1.5 weight percent or less aluminum and the remainder zinc. From another aspect, the subject invention contemplates a method for reducing the diffusion between a copper layer and a zinc base metal, said layer being in direct contact with the zinc base metal, said method comprising incorporating at least about 0.01 weight percent aluminum in said zinc base metal.

Abstract: This invention relates to a stable zinc-aluminum quaternary alloy having tensile strength well in excess of 50,000 psi and excellent machinability characteristics, the alloy being formed by subjecting the zinc-aluminum alloy containing from about 20 to 28 weight percent aluminum, from about 0.1 to 3.5 weight percent copper, about 0.01 to 0.5 weight percent magnesium and the remainder zinc, at a temperature between about 550.degree.F., and 750.degree.F., for a time to effect homogenization of said alloy, working the homogenized alloy at a temperature above the eutectoid transformation temperature, quenching the alloy, providing an effective temperature for a period of time to produce transformation into a two-phase alloy and cooling the alloy to ambient temperature.