The casting process of the bronze sacred tree unearthed in Sanxingdui is full of mystery.Held today“Sichuan Province-Campania Region Cultural Heritage Protection and Utilization Academic Seminar”Last, Guo Jianbo, a librarian from the Sichuan Provincial Institute of Cultural Relics and Archaeology, gave a speech on “Microscopic Investigation and Analysis of the Casting Process of Sanxingdui Bronzeware”, sharing the bronze casting wisdom of ancient Shu ancestors.
“The Sanxingdui No. 1 bronze sacred tree, because it is too large and very precious, we only used X-rays for analysis and testing. From the test results, it is obvious that the use of casting methods such as socket, ring casting, and split casting can be seen. , The internal casting structure can not be clearly seen.” Guo Jianbo said, the No. 2 bronze god tree, in the CT micrograph, it can be clearly seen that the use of nitration, casting, and welding technology. This connection method is quite different from the previously understood sleeve casting method. The method of forming a mechanical locking structure between the copper liquid after casting and the pin on the original casting has a similar structure to the so-called “cast riveting”.
The CT results showed that the branch attachment of No. 2 god and the branches were connected by multiple pourings. The branches are first cast and connecting holes are set at the joints, and then part of the mud core is removed for external measurement and application. The second pouring forms the branch attachments connected with the branches, and part of the copper liquid flows out of the outer wall of the stacked branches. Afterwards, part of the mud core is removed, and copper liquid is poured on the connecting part again to wrap the roots of the branches. In addition, the smaller sacred tree No. 3 analyzed its dozens of small parts one by one, and found that the crown, body, and tail of the bird’s head and bird were cast separately, and then assembled by casting.
Guo Jianbo said that through the use of CT technology, core bones were also found inside the Sanxingdui Shenshu, and the materials were judged to be organic core bones. This is also the first domestic use of CT technology to find core bones in bronzes. Guo Jianbo said that there were very few discoveries of core bone in the pre-Qin period. Was the use of core bone an innovation of local technology or the introduction of foreign cultural technology? Or local production? What is the source of CoreBone’s technology? These are all topics that need further research in the future.
Chengdu Daily·Jinguan News reporter Duan Zhentu was proofread by Li Min, edited by Song Hexiao, editor of Chengdu Museum