The process of jewelry fabrication by cold working involves intermediate annealing aimed at restoring the ductility of the alloy by recrystallization of the work hardened structure. However, the annealing treatment can lead to a coarse grained structure as a result of excessive grain-growth following the recrystallization. During manufacturing processes such as drawing or bending, deformation of the metal by plastic flow in crystals takes place. Since this flow is orientation dependent, grains with different orientation as related to the direction of the plastic flow, deform to a different extent. In a coarse-grained structure this results in a roughening of the surface known as the appearance of "orange peel".

The purpose of the work reported here, was to find additions to 14K Au-Cu-Ag-Zn alloys that will act as effective grain refiners of the recrystallized structure in a wide range of annealing temperatures and preferably also as refiners of the as-cast structure.

Author: L. Gal-Or