Change in Alloy Composition and Manufacturing Technology of Bronze Vessels Excavated from Archaeological Site

The purpose of this study is to analyze the components and observe the microstructure of 98 bronze vessels excavated from the Korean Peninsula, where such vessels were widely used, to identify the alloy composition and manufacturing process of bronze artifacts by period. In addition, we attempted to confirm the changing processes of bronze manufacturing technology by reviewing previous studies. The analysis results showed that the bronzeware of the Unified Silla period was mainly produced using a Cu-Sn binary alloy containing 20-26 wt% Sn, which was cast and slowly cooled. Also, most bronze vessels from the Goryeo dynasty were made of a Cu-Sn binary alloy, with an Sn content of 20–24 wt%. In the microstructure, a twinned α phase and β(M) phase were observed, indicating that the container was manufactured using the casting–hot forging–quenching process. Bronze vessels from the Joseon dynasty were made using a binary alloy of Cu-Sn and a ternary alloy of Cu-Sn-Pb. In order to confirm the changes in bronze manufacturing technology over time, we investigated the alloy composition and microstructure of a total of 295 vessels, including previous studies, and were able to confirm the dominant production technology for each period. During the Unified Silla period, the shape of the container was made by casting using a Cu-Sn binary alloy, and the process was completed through slow cooling or quenching. During the Goryeo Dynasty, vessels were made using a Cu-Sn binary alloy through a process of casting, hot forging, and quenching, or by casting a Cu-Sn-Pb ternary alloy into a vessel shape and then slowly cooling it. And in the Joseon Dynasty, the use of ternary alloys of Cu-Sn-Pb increased.