In the Civic Museum of Palazzo Schifanoia in Ferrara a collection of 1104 coin striking tools is stored. Among these, five steel dies representative of the activity of the Mint of Ferrara from the 2nd decade of the 17th to half of the 18th century have been chosen and studied. In that period, while important innovations in the coin minting technique were introduced in Europe, Ferrara declined from the rank of ducal mint to that of peripheral minting centre of the highly centralized Papal States. This research presents technical argumentations in order to both properly place the activity of the Papal Mint of Ferrara in the international scenery and to promote greater attention to the local coinage systems, as up to now only scarce attention has been devoted to the metallurgy of coinage tools. The metallic alloys used in the dies have been characterized by metallographic and microhardness analyses. The results suggest that the minting dies have been produced by a manual smithing technique consisting in hammer hot forging, followed by punching and chiseling operations, necessary to produce the coinage type, in negative form. Proper final thermal treatments have mainly induced a martensitic microstructure on the coinage head, where high hardness values (from 918 to 1009 HV0.3) guarantee optimal minting conditions, and a ferritic/pearlitic microstructure in the other end, the side subjected to hammer strokes, where a good toughness is ensured in order to delay cracks and fracture.
A PRELIMINARY ANALYSIS OF SOME MINTING DIES PRODUCED UNDER PAPAL RULE IN FERRARA
MONTICELLI, Cecilia;BALBO, Andrea;VACCARO, Carmela;GARAGNANI, Gian Luca
2012
Abstract
In the Civic Museum of Palazzo Schifanoia in Ferrara a collection of 1104 coin striking tools is stored. Among these, five steel dies representative of the activity of the Mint of Ferrara from the 2nd decade of the 17th to half of the 18th century have been chosen and studied. In that period, while important innovations in the coin minting technique were introduced in Europe, Ferrara declined from the rank of ducal mint to that of peripheral minting centre of the highly centralized Papal States. This research presents technical argumentations in order to both properly place the activity of the Papal Mint of Ferrara in the international scenery and to promote greater attention to the local coinage systems, as up to now only scarce attention has been devoted to the metallurgy of coinage tools. The metallic alloys used in the dies have been characterized by metallographic and microhardness analyses. The results suggest that the minting dies have been produced by a manual smithing technique consisting in hammer hot forging, followed by punching and chiseling operations, necessary to produce the coinage type, in negative form. Proper final thermal treatments have mainly induced a martensitic microstructure on the coinage head, where high hardness values (from 918 to 1009 HV0.3) guarantee optimal minting conditions, and a ferritic/pearlitic microstructure in the other end, the side subjected to hammer strokes, where a good toughness is ensured in order to delay cracks and fracture.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
