Metallographic studies of copper based scraps from the Late Bronze Age Santa luzia archaeological site (Viseu, Portugal)

Once metal was recognized as a new material in prehistorical times metallic artifacts began to be made and the metallurgical skills started to develop. Metallurgical scraps found in archaeological sites normally evidence metallurgical production of artifacts in situ. Studies of metal scraps can reveal the different stages of thermo-mechanical treatments that the artifacts were subjected to in order to obtain a selected shape and hardness. While for metal artifacts sample taking can be problematic, sample taking in metallurgical scraps can be easier since scraps have normally no artistic/esthetical display value. Additionally, corrosion phenomena can be evaluated in scraps that frequently have not been subjected to any conservation treatment. This paper deals with metallographic (optical and electron microscopy), EDS-SEM and EDXRF studies that have been undertaken in copper based metallurgical bars of circular and square sections from Santa Luzia site, in central Portugal.