Research on the corrosion of bronze weapons from the pits of the terracotta warriors

Abstract

Large amounts of bronze weapons have been unearthed from the pits of the Terracotta Warriors. Though they are of the same period, their condition is quite different; some are slightly corroded; some have almost no corrosion with a gray-black or green-gray surface; some are badly corroded. ICP, XRD, SEM, EDX, XRF, AES and Metalloscope were employed on seven bronze weapons to investigate their composition, structure and differences between the surfaces and bulk metals. Results showed that all these bronze weapons are high-tin bronzes. The three bronze swords contain a higher tin content than the others and have undergone heat treatment, which gives them the necessary tenacity of weapons. The surface layers of the weapons are rich in tin in various degrees because of selective corrosion and the migration of copper ions during corrosion. Some objects are more corrosion-resistant by a quenching treatment and the formation of compact tin oxides. © 2011 Materials Research Society.