New insights into the manufacturing technique and corrosion of high leaded antique bronze coins

Further studies focused on the analysis of the corrosion phases - combining results from μ-XRD and neutron diffraction investigations - as well as on the manufacturing techniques of the antique Greek coins. The μ-XRD analysis applied a beam spot of 300 μm allowing for a localised determination of corrosion phases on the surfaces of the objects. The main corrosion products consist of metal (Cu, Pb, Cu/Sn) oxide phases. As minor components also metal sulphide and chloride phases could be assigned. To enable the distinction between different manufacturing techniques 35 coins and eight self-made 'replicas' were analysed in a non-destructive way by bulk neutron texture analysis which reveals changes in the microcrystalline structure of the alloys related to the mechanical minting processes.