铜质文物上含钠复盐类腐蚀产物形成原因探析OACHSSCD

Copper-based cultural relics exhibit a variety of corrosion products.In addition to the well-known"bronze disease"and other chlorine-containing corrosion products,the occurrence of sodium-containing double salt corrosion products in recent years has also attracted widespread attention.In this study,a variety of laboratory analysis methods were used to examine corrosion products on multiple copper-based artifacts.In combination with relevant literature,several common Cu-Na corrosion products were summarized,including chalconatronite[Na2Cu(CO3)2·3H2O],sodium copper formate hydroxide oxide hydrate[Cu4Na4O(HCOO)8(H2O)4(OH)2],sodium copper carbonate acetate[NaCu(CO3)(CH3COO)],and others.The causes of their formation and the sources of sodium were classified,including casting processes,burial environments,usage conditions,conservation treatments,and material interactions in composite artifacts.This provides support for improved conservation and preservation of cultural relics.For the first time,ion introduction during modern metal casting processes is discussed as a potential factor that can lead to corrosion under certain conditions,and the mechanism of its formation is further elaborated.A blue-purple corrosion product,juangodoyite[Na2Cu(CO3)2]was identified for the first time by Raman spectrometry,and its formation mechanism was discussed.