NIOBIUM FOR COINS

摘要

This article is taken from the paper written by Mr Robert Grill of Plansee SE and Mr Alfred Gnadenberger of the Austrian Mint, Vienna, and presented by Mr Grill at the T.I.C. meeting in Innsbruck Niobium was selected as core metal for a special 25 euro bimetallic coin-collector series issued by the Austrian Mint, and the coloured niobium insert is a special feature. Silver is used-as the surrounding metal. The 25 euro coin is legal tender in the Austrian republic. The combination of these materials with distinctly different material properties, especially deformation behaviour, and the use of the coloured niobium insert makes an adaptation of production parameters and manufacturing philosophy necessary. The paper describes the experience gathered during project definition, establishment of the production line and production of the bi-metallic coins.