Zhang Lei, Chen Yile, Zheng Liang, Zheng Ruyi
School of Civil Engineering and Architecture, Wuyi University, No. 358 Baihua Road, Wuyishan 354300, China.
Faculty of Humanities and Arts, Macau University of Science and Technology, Avenida Wai Long, Tapai, Macau 999078, China.
Materials (Basel). 2025 Jan 16;18(2):402. doi: 10.3390/ma18020402.
The ruins of the Imperial City of the Minyue Kingdom were an important site of the Minyue Kingdom during the Han Dynasty. Characteristic bronze arrowheads unearthed from the East Gate, with their exquisite craftsmanship, provide important physical evidence for studying ancient bronze casting technology and the military activities of that time. However, there is still a lack of systematic research on the alloy composition, casting process, and chemical stability of these arrowheads in long-term burial environments. The bronze arrowheads that were found in the East Gate warehouse are the subject of this study. Metallographic analysis, scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) were used to carefully examine their composition and microstructure, as well as the casting process characteristics. The findings reveal the following: (1) The East Gate bronze arrowheads primarily consist of copper-tin binary alloys, and certain samples exhibit a lead (Pb) content of up to 11.19%, potentially due to element addition during casting or element migration in the burial environment. (2) The metallographic structure shows that the sample matrix has a typical α-dendrite structure, indicating that a high-temperature casting process was used, and then a certain surface treatment was performed to enhance corrosion resistance. (3) Under a scanning electron microscope, it was observed that a three-layer structure was formed on the surface of the arrowhead, including a fully mineralized layer, an intermediate transition layer, and the original core tissue. (4) The detection of molybdenum (Mo) in some samples suggests a close relationship between the complexity of the buried soil environment and human activities. (5) By comparing the microstructure and corrosion degree of the longitudinal section and the cross-section, it was found that the longitudinal section has a stronger corrosion resistance due to its denser structure. Comprehensive analysis shows that the technical details of the bronze arrowheads unearthed from the Minyue Imperial City in terms of material selection, casting process, and later use reflect the outstanding achievements of the Minyue Kingdom in the field of bronze manufacturing in the Han Dynasty.
闽越国王城遗址是汉代闽越国的重要遗址。从东门出土的具有特色的青铜箭头，工艺精湛，为研究古代青铜铸造技术和当时的军事活动提供了重要实物依据。然而，对于这些箭头在长期埋藏环境下的合金成分、铸造工艺以及化学稳定性仍缺乏系统研究。本研究以在东门仓库发现的青铜箭头为对象，运用金相分析、扫描电子显微镜（SEM）和能谱分析（EDS）仔细研究了它们的成分、微观结构以及铸造工艺特点。研究结果表明：（1）东门青铜箭头主要由铜锡二元合金组成，部分样品铅（Pb）含量高达11.19%，这可能是由于铸造时添加元素或埋藏环境中元素迁移所致。（2）金相组织显示样品基体具有典型的α枝晶结构，表明采用了高温铸造工艺，之后进行了一定的表面处理以增强耐腐蚀性。（3）在扫描电子显微镜下观察到箭头表面形成了三层结构，包括完全矿化层、中间过渡层和原始核心组织。（4）部分样品中钼（Mo）的检测表明埋藏土壤环境的复杂性与人类活动之间存在密切关系。（5）通过比较纵截面和横截面的微观结构与腐蚀程度，发现纵截面结构更致密，耐腐蚀性更强。综合分析表明，闽越国王城出土青铜箭头在选材、铸造工艺及后期使用等方面的技术细节，反映了汉代闽越国在青铜制造领域的杰出成就。
