东周时期青铜剑首同心圆的制作技术研究

Study on the making technique of bronze pommels decorated with concentriccircles in the Eastern Zhou period

东周时期盛行佩剑之风 ,在剑上集中了多项杰出的装饰技术 ,其中位于青铜剑首端部的同心圆装饰以其精湛的制作技术引起了科技史界的关注。剑首同心圆由多圈高同心度、高凸起、薄壁状凸棱组成。对东周时期的多件剑首同心圆的考察表明剑首同心圆应用了类似轮制法成形工艺 ,预先单独铸造成形 ,后与剑茎铸接成一体。通过对车削法、石范铸造、失蜡铸造、陶范铸造等剑首同心圆可能的成形方法的分析 ,推测古人很可能不预制陶模 ,而是用轮制法直接车制出具有同心圆的剑首陶范 ,以陶范铸造法铸造剑首同心圆 ,此法是东周时期最可行的成形方法 ,其基础是新石器时代已采用的轮制法制陶技术及商周时期成熟的陶范处理技术。通过模板轮制法的模拟试验 ,成功地复制了青铜剑首同心圆。其过程为配制极细的泥料、制作带齿的模板、采用轮制法制作同心圆陶范并在相应的凸棱上刻下绳纹、焙烧陶范与浇注青铜液。

The concentric circles decorated at the pommel were made of many thinwall threadrelief circles with very regular distribution. Their thickness is only about 0.2～0.8mm, relief height about 0.5～2.2mm, gap only 0.3～ 1.2mm. The concentric circle number is different. There were as many as 11 circles in some sword pommels. Some pommels collected by Shanghai Museum were observed and studied. The thinwall threadrelief circles have a high concentricity. It indicated that a kind of wheelmade method was adopted. And it was found this kind of pommels was cast only. Several casting methods for making pommels with concentric circles are discussed in this paper. The stone mold casting is just for making simple bronze tools or coins. In the lostwax process, it is very difficult to form so sharp thread relief wax models and get a concentric circle clay mold from a wax model. Maybe only clay mold casting method is the making technique of concentric circle pommels. A pottery wheel could be used to make a pommel clay mold with threadrelief circles. As early as in Longshan culture period of Neolithic age, some highhandle cups had a very thin wall even it's thickness is just 0.3mm, like eggshell. These cups were made by wheel. So concentric circle pommels could be made by the same wheelmade techniques in the Eastern Zhou period. Several making clay molds methods were experimented and then one could produce the concentriccircle clay mold was found. Firstly, prepare clay mold materials. Secondly, making two templates. Thirdly, using a pottery wheel to making a pommel clay mold with threadrelief concentric circles. Carving the ropelike pattern on some relief. Making an upper clay mold by wheel. Baking them and combining them. Pouring liquid bronze into the cavity and a bronze pommel with concentric circles was produced. Clay properties and superb skill were the key to a successful production of this kind of pommels.