| Title |
Chronological Changes in the Alloy Composition and Microstructure of Bronze Mirrors |
| Authors |
김소진(So Jin Kim) ; 한우림(Woo Rim Han) ; 홍주현(Ju Hyun Hong) |
| DOI |
https://doi.org/10.3365/KJMM.2026.64.9.826 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Bronze mirror; Microstructure; Chemical composition; Materials; Non-metallic inclusion(NMI) |
| Abstract |
This study characterized bronze mirrors dating from the Early Iron Age to the Goryeo Dynasty through chemical composition analysis and microstructural observation. The 30 analyzed mirrors consisted of copper-tin-lead (Cu-Sn-Pb) ternary alloys, exhibiting distinct compositional and microstructural variations depending on the period. Mirrors from the Early Iron Age contained an average of over 20.8 wt.% tin (Sn) and 5-7 wt.% lead (Pb), with microstructures composed of δ and α+δ phases. From the Three Kingdoms and Unified Silla periods onward, the tin (Sn) content of the alloy materials decreased, whereas the lead (Pb) content increased, resulting in a microstructure consisting of an α-phase matrix and an α+δ eutectoid structure. To examine temporal changes in materials and manufacturing techniques, the alloy compositions and microstructures of a total of 76 bronze mirrors were evaluated, incorporating data from previously excavated artifacts. The analysis confirmed that bronze mirrors produced during the Early Iron Age-when mirror production originated can be chronologically distinguished from those of subsequent periods based on these compositional and structural differences. However, given the limited sample size, further research incorporating a broader range of bronze artifacts with well-documented provenance and chronology is required to fully elucidate the historical evolution of alloy compositions and microstructures. |