Metallurgical Investigations on Two Sword Blades of 7th and 3rd Century B.C. Found in Central Italy

Abstract

This study aims at casting new light about the knowledge of the metallurgical techniques developed by the Etruscan and the Romans during their political and cultural interactions in Central Italy. The analysis of two weapons found at the Etruscan sites of Vetulonia and Chiusi have pointed out some new information about the production process performed. The optical microscopy analysis has allowed to identify the sequence of the microstructural constituents present in the two ancient weapons. SEM-EDS has permitted to identify the chemical composition of the non metallic inclusion and to estimate the average temperature of the reduction process. The analysis of the metal matrix performed by a coupled argon plasma spectrometer permitted to measure the average chemical compositions of the studied alloys. SEM-EBSD analysis has allowed to identify the crystallographic textures present within the different zones of the sword blades and this has indicated the realization of a forming process that gave interesting mechanical properties to the metal products. The results obtained by the Etruscans artisans were of very high standard quality and their production system had been certainly assimilated by the Romans who found in them a strategic factor to increase their power.

Archaeometallurgical Investigation of Joining Processes of Metal Objects from Shipwrecks: Three Test Cases

“…A high volume fraction of inclusions was observed near the forge-weld line of cross-section A2-A2 (Fig. 5e), indicating a forged-welding zone [2,3]. Higher magnification of the slag inclusion demonstrated two-phase wüstite-glass slag inclusions (Fig.…”

“…1) may indicate welding zones between two or more different aferritic layers due to the high volume fraction of slag inclusions, and the finer a-ferritic grains at the welding zone, as shown in Fig. 1(b) [2,3].…”

“…The welding zone between two different iron layers of dissimilar compositions is characterized by a higher volume fraction of the non-metallic inclusions and a finer grain size than in the main body of the metal. This is not the case when the compositions of the layers are similar [2,3,16]. When two or more strips are forge-welded together, the oxides are trapped between them, forming a relatively continuous layer [17].…”

“…Archaeometallurgical studies of ancient metal objects manufactured by joining techniques have been carried out [1][2][3][4]; however, it is rare to find a broad review on the subject. It is even more challenging to review joining techniques of metal objects retrieved from shipwrecks which have lain for centuries on the seabed.…”

Electron backscattering diffraction as a complementary analytical approach to the microstructural characterization of ancient materials by electron microscopy

“…The earliest references in the literature correspond to the research by Mapelli, Nicodemi and co-workers on ancient swords and nails aimed at improving knowledge of the metallurgical techniques related to iron materials [18][19][20][21]. EBSD enabled the orientation map of each scanning area to be defined and to determine the Orientation Distribution Function (ODF).…”