Stress corrosion cracking in ancient silver

摘要

Six cases of ancient silver embrittlement by corrosion are discussed with respect to evidence for stress corrosion cracking. Both intergranular and transgranular cracking can occur, depending on whether there is retained cold-work in the silver. The severity of cracking is influenced by a combination of factors, including the amount of cold-work in the silver and the burial environment. The burial environment is important for two reasons. Firstly, the soil weight can induce high stresses, particularly in hollow, thin-walled, and incompletely filled-in artefacts. Secondly, grave burials can result in more aggressive soil environments owing to high salinity from body decomposition.