Characterization of corroded bronze Ding from the Yin Ruins of China

This paper presents the result of scientific examinations carried out on the soil-buried archaeological bronzes Ding from Yin Ruins of China. Eight of typical fragments from different bronze Ding were selected as researched samples according to their deterioration characteristics. Optical microscopy (OM), scanning electron microscopy coupled with energy (SEM-EDX), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were used to understand the corrosive morphological characteristics, to clear the nature of patina and to analyze the elementary composition of bronze Ding. The results indicated that it is not possible to distinguish the original lustrous metallic surface in most samples because of the corrosive crust. The substrate of bronze Ding contains74-86% Cu, 1.1-4.6% Pb, and 10-18% Sn, which is in agreement with the historical investigation in the ritual vessels of Shang time. Copper-containing compounds were the main constituents of natural patina: Cu2(OH)3Cl existed as corrosion product in all the powdery or crack surface; Cu2(OH)2CO3 was the main corrosive product in a compact and hard corrosive surface. This study provides useful information for the restoration and protection of bronze Ding in Yin Ruins