东周青铜复合剑制作技术研究

东周时期,吴越出现了一种奇特的青铜复合剑,剑的中脊和两刃是用两种不同成分的青铜铸接而成。为充分了解青铜复合剑的制作,对上海博物馆馆藏的4把青铜复合剑残剑进行了分析,通过X-射线荧光能谱仪分析残剑的剑刃和剑脊的成分,金相显微镜分析剑刃和剑脊的组织,发现中国古代工匠采用低锡青铜制作韧性好的剑脊,高锡青铜制作强度和硬度高的剑从,通过榫卯结构以铸接法将剑脊与剑从结合成一体,得到刚柔兼具的青铜复合剑。在测试分析的基础上进行模拟实验,先以陶范铸造法铸造出两侧带榫头的青铜剑脊,剑脊的成分采用88％铜、10％锡、2％铅的低锡青铜;然后将青铜剑脊置入铸造剑从的陶范内,两侧的榫头伸入陶范型腔中,剑从的成分采用78％铜、20％锡、2％铅的高锡青铜,当剑从凝固时产生的收缩使剑脊和剑从牢固地结合成整体,再分1次或多次以铸接法铸上剑格、剑茎、剑箍和剑首,成功地复制了青铜复合剑,再现了东周时期青铜复合剑的制作工艺。

Study on bimetallic bronze swords in ancient China

As early as in Shang Dynasty (1600 - 1100BC) of China, there appeared bimetallic weapons formed by forged anode iron and bronze. This was the earliest combinative metal weapon in China. The formulas of Liu - chi in the K' ao Kung Chi, Zhou Li, specify the copper and tin contents of bronze according to various kinds of bronze articles. The K' ao Kung Chi, Zhou Li, was recorded in the Eastern Zhou (770 -221 BC)period,which showed that ancient Chinese had fully understood the relationship between bronze alloy and its properties at least in Eastern Zhou period. They could change the copper or tin content to get good bronzes. The bimetallic bronze weapons produced in Eastern Zhou were the creative application of the relationship between alloy composition and its properties. The blade of bimetallic bronze sword was cast with different composition of alloy from the cutting edge. In this paper, the research on them was introduced with the help of modern examinations and simulation experiments. It can been scan that the blade and cutting edge were all jointed with mortise and tenon from the cross section of fragmetns. The compositions of blade and cutting edge were tested by XRF. The lower - tin bronze formed blade with good toughness and the higher - tin bronze formed cutting edge with high hardness and strength. Microstructures were obseved by microscope and found that the normal cast dendrite of bronze is seen on the cutting edge and blade. The structure of blade is much coarser than that of the cutting edge. From the microstructure, it could be concluded that the cutting edge was not treated by heat after cast for its dendrite was clear and fine. The blade should be annealed in high temperature after cast for its dendrite was not clear and became coarse. After annealing, the brittle delta phase in the blade reduced, while the plasticity and toughness of blade increased evidently, resulting in a good resistance to shock. After some simulation experiments, we successfully restored the making technology and reproduced some bimetallic swords. Firstly, making two clay moulds to cast a blade in 88% copper, 10% tin and 2% lead with tenon. And then,making two clay moulds for cutting edge with the bronze blade in the cavity. Liquid bronze in 78% copper,20% tin and 2% lead was poured into the cavity. After solidification and shrinkage,the cutting edge tightly surrounded the tenon of spine. Finally, moved the assembly of spine and cutting edge out of the clay mould when it is cooled. Polishing the sword surface and cutting edge. Putting it into the clay mould again for casting the guard, grip and pommel. Then a bimetallic sword was finished. By casting in steps, a bimetallic sword was produced with both rigidity and flexibility. Making bimetallic swords show that the influence of tin content on bronze mechanical properties had been fully understood by the Chinese ancients.