Metallographic and microstructural investigation on copper based nails of the Roman Empire Age

¹ Dipartimento di Meccanica, Politecnico di Milano, via La Masa 34, 20156 Milano, Italy
e-mail: carlo.mapelli@tiscali.it
² Soprintendenza per i Beni Architettonici, Paesaggistici, Storici, Artistici ed Etnoantropologici per le province di Pisa e Livorno, via Lungarno Pacinotti 46, 56126 Pisa, Italy

Received: 10 January 2012
Accepted: 4 April 2012

Abstract

The scientific investigation involves the examination of copper alloy nails dated back to the Roman Age. The artifacts were retrieved from a shipwreck discovered offshore Elba island (Italy). Further carbon dating measurements indicated the origin between 140 and 300 AD. This work includes a brief overview of the ship’s routes and fortunes in order to give some context to the metallographic investigations. The experimental procedure involves the use of both Optical and Scanning Electron Microscopy (OM and SEM) coupled with EDS and EBSD probes. The attention has been focused on the metallurgical features of the nails with the intent of casting some light on the metalwork processes of the Roman Age. The scientific trials revealed a “brazed” joint, which allowed to learn more about the applications of this technique during this historical period. In addition, the textural analysis yielded a strong work-hardening, evidence of an intense cold shaping procedure in use by the Roman blacksmiths.