Functions and Morphology of Metal Lead Addition to Ancient Chinese Bronzes
The typical morphology of metal lead (Pb) in ancient bronzes made in the Spring-Autumn Warring States Period (770 B.C. –221 B.C.), China, was examined by using electron microscopic techniques. We propose that the main purposes for adding metallic Pb in a large quantity into ancient bronzes such as arrows and ritual vessel-Ding were for increasing weight and economical reasons. SEM observations from the fracture surface of the bronzes revealed that the Pb particle possessed a “hollow–cored bubble” structure, which was formed due to absorbing casting gases during solidification and therefore indirectly eliminated the casting porosity and loosen.
Young Won Chang, Nack J. Kim and Chong Soo Lee
C. X. Pan et al., "Functions and Morphology of Metal Lead Addition to Ancient Chinese Bronzes", Advanced Materials Research, Vols. 26-28, pp. 523-526, 2007