Patent ID: 7498543
Filing Date: 2009-03-03
Classification: B23K

Abstract:
1. A method of joining or repair of a metal surface laminate construction, the laminate construction comprising a metal sheet with an outer metal surface layer and an opposing surface layer to which a polymer layer is bonded, the polymer layer being coextensive with the opposing surface layer, the metal sheet having a thickness up to about one-half millimeter and the polymer layer being no thicker than the metal sheet, the method comprising the steps of: (a) providing at least a first laminate construction comprising at least a first outer metal surface layer with at least one polymer layer disposed on an opposing sheet surface layer below the first metal outer surface layer; (b) defining a desired weld line along said the first outer metal surface layer in which weld filler metal is deposited in contact with polymer material of the polymer layer; and (c) applying a substantially continuous weld along the defined weld line, by use of cold metal transfer gas metal arc welding, wherein a weld wire of filler metal comprising a zinc based alloy is cyclically inserted and withdrawn from a weld pool during weld application in coordination with activation and deactivation of arc heating, such that arc heating is terminated when the weld wire contacts the weld pool and arc heating is reactivated when the weld wire is withdrawn from with the weld pool, such that heat input to the laminate construction is limited for the purpose of minimizing thermal damage to the polymer material in the vicinity of the weld.