Search Results (3)

This study investigates the material properties, metallurgical processes, and corrosion mechanisms of bronze arrowheads excavated from the Imperial City of the Minyue Kingdom, a UNESCO World Heritage site in Wuyishan, Fujian, China. Using optical microscopy, SEM-EDS, XRF, XRD, and Raman spectroscopy, the researchers analyzed the cross-section and corrosion layers of the artifacts. Results show that the arrowheads are Cu-Sn-Pb alloys, with Cu (70.76%), Sn (8.73%), and Pb (8.72%), optimizing hardness, toughness, and casting performance. Corrosion analysis reveals a surface layer rich in Cu₂O, CuO, SnO₂, and Cu₂(OH)₂CO₃, driven by oxidation, carbonation, and sulfidation reactions. The corrosion layer exhibits stratification, porosity, and cracks, indicating the influence of oxygen, carbonate ions, and sulfides in burial environments. This study provides crucial insights into ancient bronze metallurgy and the long-term preservation of cultural relics. Full article

X-ray Computed Tomography (X-CT) is now an established technique for the investigation and diagnostics of Cultural Heritage. Its advantages include non-invasiveness, non-destructiveness, and the possibility of exploring the inner parts of an object without any modification. X-CT is often employed to investigate the construction methods of complex artifacts made with different parts or materials, but it is also able to support the analysis, intervention, monitoring and enhancement processes of artworks, creating digital models that can aid in the conservation and restoration procedures. In this work, several case studies are presented in which the CT technique has been decisive in identifying the effects of time and the events that occurred during the object’s life influencing its state of conservation. These range from large objects, such as an 18th century CE writing cabinet or an ancient Egyptian wooden coffin, to very small artifacts, like Mesopotamian lapis lazuli beads or fragments of Roman colored glass. Additionally, the results obtained by µ-CT investigations on the conservation state of a bronze arrowhead uncovered from the Urama-chausuyama mounded tomb (Japan, Kofun period, end of the 3rd century CE) are presented here for the first time. Lastly, the versatility of the technique when applied with different setups is highlighted. Full article

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. Full article