NICKEL PLATED ZINC ALLOYS FOR COINAGE

摘要

A lower melting point metal substrate such as zinc is covered with a higher melting point metal layer such as nickel. In order to render the nickel layer suitable for coining without cracking, it is quickly annealed with a burst of induction heat. The induction heat is limited so that only the metal layer is heated without allowing substantial heat transfer to the metal substrate. This protects the metal substrate from any substantial melting, deformation or warping and maintains the metal substrate substantially in tact and without a change in properties and shape.