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Archaeological metal

Fabrication techniques and conservation of archaeological metals.

The impact of conservation treatments on bronze objects from antiquity is rarely researched. Janneke Nienhuis took on this task from a materials science perspective for her doctoral thesis. She posed several questions in which material analysis, characterization, perception and valuation were central.

Cross-section of an embedded bronze leg from Zevenbergen.

Cross-section of an embedded bronze leg from Zevenbergen. Top: Optical micrograph, showing a white layer covering the bulk, which consists of several coloured grain-like structures. Bottom: Backscatter electron image showing a corroded grain-like structure in which the grains seem to be detached from each other. A continuous outer layer is seen as well.

Cross-section of an embedded bronze leg from Zevenbergen. Top: Optical micrograph, showing a white layer covering the bulk, which consists of several coloured grain-like structures. Bottom: Backscatter electron image showing a corroded grain-like structure in which the grains seem to be detached from each other. A continuous outer layer is seen as well.

All objects are made of materials containing evidence of their past. Furthermore, archaeological finds are especially sensitive to adverse external influences, such as corrosion. The knowledge of fabrication processes, ageing and conservation interventions contributes to an improved preservation of these objects for the future.

Bronze coatings

The main question of the study was, 'What is the impact of a conservation treatment on the material properties of archaeological bronze?’ Various types of anti-corrosion agents and coatings are used to protect against the deterioration of bronze. However, these coatings can significantly hamper further research on the objects. The sub-project 'Bronze coatings' investigated the causes of visually disturbing effects and possible solutions were suggested.

Iron nails

Project: research into the typology, fabrication and origin of iron nails from three Roman shipwrecks. One of the research questions was whether these vessels could have been built during the same period and at the same shipyard. Seven different types of nails were found in the ships' wood. Samples were taken of the most common type in order to examine the fabrication technique and origin.

Origin

The chemical composition of iron and inclusions in the nails were measured using EDS (Energy Dispersive X-ray Spectroscopy) coupled with a Scanning Electron Microscope (SEM) and LA-ICP-MS (Laser Ablation Inductively Coupled Plasma Mass Spectrometry).
This proved that the nails from two ships are similar. However more research is required in order to attribute both Roman ships to the same shipyard.