Metallurgical Study on Slim Bronze Dagger Excavated from Wonjangdong, Jeonju

Abstract

Background/Objectives: This study reports the of microstructure and chemical components analysis of three pieces of slender bronze daggers and one piece of slender bronze dagger fragment excavated at Jeonju Wonjang-dong. Methods/Statistical Analysis: This study has conducted microstructure analysis and component analysis for slender bronze daggers from the perspective of metallographic and compares its outcomes with precedent research to examine the similarities and differences in terms of characteristics and manufacturing methods of slender bronze daggers. The structure analysis tests were done via optical microscopes and SEM (Scanning Electron Microscope) after the process of abrasion and collision. While, chemical composition of the samples was measured by EDS (Energy Dispersive Spectrometer) attached to the SEM. Findings: As a result of analyzing the microstructure, the study observed arborization structure in all of three pieces of slender bronze daggers and one piece of slender bronze dagger fragment, but not the trace of heat treatment or processing, and so the study judged that all of these had the cast structure. In the meanwhile, the component analysis found that these relics were made of ternary alloys of Cu-Sn-Pb (Cu 74-78%, Sn 18-22%, Pb 3-4%) with small content of As and S. All four pieces of analysis samples had more content of Sn and less of Pb, compared to general alloy composition scope (Sn 6-20%, Pb 5-10%) of bronze daggers so far reported. Improvements/Applications: This suggests the probability of the existence of human groups that wielded the unique bronze ware techniques of making such hard weapons as to stand repeated shocks at the time.