The purpose of this paper is to investigate the surface corrosion products of copper alloys by non‐destructive techniques (NDT) and correlate them with their bulk composition.
Specimens of copper alloys, whose compositions were close to those of ancient copper‐based artefacts, were left to be corroded in simulated soil solution containing ammoniacal buffering solution of pH =10 in 1:1 ratio, in order to accelerate the corrosion rate. The elemental compositions of the surface corrosion products were determined versus time using X‐Ray Fluorescence Spectroscopy, and the surface morphology by Scanning Electron Microscopy with Energy Dispersive X‐Ray Micro‐detector methods, and the results were compared to the bulk composition, as measured by Atomic Absorption Spectroscopy and Inductively Coupled Plasma Atomic Emission Spectroscopy.
During the corrosion evolution of the copper alloys in the corrosive solution, transitional phenomena were observed such as an initial decrease of the copper concentration with a simultaneous increase of the concentrations of the secondary alloying metals (Sn, Zn and Pb). After 30‐60 immersion days, the alloy concentrations were stabilised.
The results of this research could contribute to the non‐destructive characterisation of copper‐based ancient artefacts (from which the taking of samples is not allowed).
