摘要
由在部分锥足圆鼎上残留的浇口痕迹可知,商前期的浇注系统设置在腹部两块范的合范处,鼎侧放浇注。至商前期晚段(商中期)开始,浇口从腹部两块外范的合范处逐渐改变为鼎足底端,鼎倒立浇注。对于浇口设置在鼎腹部和鼎足底的不同浇注系统,运用计算机模拟技术对青铜鼎铸造过程进行流动模拟和凝固模拟,比较在不同浇注系统条件下青铜圆鼎的充型和凝固收缩过程。浇口设置在鼎腹部时,较多的分散液流在二足和相近的下腹部汇流导致这些部位集中了较多的冷隔区而产生铸造缺陷。浇注系统对青铜鼎的铸造充型和凝固过程有很大的影响,这是商早期青铜鼎浇口从设置在鼎腹部转变为商中期之后设置在鼎足底的主要原因之一。
In the early Shang Dynasty,traces of pouring gates on excavated bronze round tripod vessels indicate that the gating system was originally set on the belly.From the middle Shang Dynasty,the pouring gate gradually shifted from the belly to the legs,and bronze round tripod vessels were cast in an inverted orientation.This study compared the filling and solidification behaviors of bronze round tripod vessels under different gating-system configurations through computer simulations.Based on a late Shang Dynasty bronze round tripod in the collection of Shanghai Museum,a three-dimensional CAD model was constructed.Drawing on the investigation into the gating system of Shang Dynasty bronze tripods,three different pouring-gate configurations were designed:1)a single pouring gate on the belly;2)a single pouring gate on one leg;3)two pouring gates on two separate legs.Under the same pouring temperature and velocity,computer simulation experiments were conducted for all these three schemes.When the pouring gate was set on the belly,the simulation revealed extensive cold-shut defects on the large areas of the belly and on the two legs farthest from the pouring gate.These defects resulted from dispersed molten bronze streams converging in these regions during filling.Such convergence increased the likelihood of cold shuts and related casting defects in bronze tripod.When the pouring gate was set on a single leg,misrun and cold-shut defects occurred at the belly bottom near the ungated legs and on the two ungated legs.It was an improvement compared with the belly-gate configuration.When the pouring gates were set on two legs,only minor cold-shut defects appeared.It was a significantly improved filling process.In terms of solidification,all the three pouring-gate configurations produced shrinkage defects,especially at the parts such as the two ears,the three legs,the junctions of the rim and the ears,and the thicker decorative regions.Changing the position of the pouring gate had limited influence on these solidification-related defects.Therefore,applying the principle of uniform wall thickness,such as using hollow legs and hollow ears,would help reduce the occurrence of shrinkage defects.The design of the gating system had a significant effect on the casting quality and filling process of Shang bronze tripods.Setting the pouring gates on the legs of the round tripod vessel proved superior to placing them on the belly,offering a key explanation for the evolutionary shift in gating-system design during the Shang Dynasty.
作者
廉海萍
LIAN Haiping(Shanghai Museum,Shanghai 200003,China)
出处
《文物保护与考古科学》
北大核心
2025年第6期1-15,共15页
Sciences of Conservation and Archaeology
基金
国家社科基金后期资助项目(20FKGB003)资助。
关键词
青铜鼎
铸造
浇注系统
计算机模拟试验
商代
Bronze tripod vessel
Casting
Gating system
Computer simulation experiment
Shang Dynasty
