Research on the alloy composition of casting of bronze ware
What are the main components of ancient chinese bronze smelting and casting technology?
In ancient China, Native copper was first used. In the early Shang Dynasty, bronze with copper tin alloy could be made by fire. The process of smelting bronze is relatively complex. It is likely that the selected ore is first added to the flux, then placed in the smelting furnace, burned with charcoal for smelting, and when the heat is mature, the refined copper liquid is taken and the slag is discarded to obtain the initial copper. The initial copper is still relatively coarse and needs to be further refined to obtain pure red copper. Bronze is made by melting red copper with tin and lead to form an alloy.Thtis bronze gave birth to ancient Chinese bronze wares.
Let's talk about the alloy composition.
The so-called alloy refers to the fusion of two or more metals at high temperatures to form another metal, which possesses new physical and chemical properties. Alloys belong to the category of recreation in casting, and bronze is the pioneer of alloys.
Bronze is generally an alloy of copper and tin, also known as tin bronze. But many tin bronze in ancient China often contained a small amount of lead, which is a characteristic of the Shang and Zhou bronze casting, that is, the melting point of the bronze was lowered. Of course, the significance lies not only in reducing the melting point, but also in the demand for alloy hardness. The proportion of alloy composition of ancient Chinese bronzes was first found in Kao Gong Ji. The book has a unique and detailed record of the production practices and experience knowledge of the laboring people in the pre Qin era, and is an archive of production technology. Kao Gong Ji records that there are different tin contents in six kinds of bronzes, which is called "Liuqi". The proportion of these six different alloys is: six parts of the Zhongding are gold and one part of tin:
Five parts of an axe and a catty are equal in gold and one in tin;
The Qi of Ge Ji is divided into four parts, with gold and tin ranking first;
The Qi of the Great Blade is divided into three parts, with its gold and tin ranking first;
The fifth part of the cutting and killing arrows ranks second in gold and tin;
Jian Sui is half gold and half tin.
In ancient times, people called copper gold, so gold in Kao Gong Ji refers to pure copper. The combination of gold and tin in the Six Qi is called tin bronze, which also indicates the fusion ratio of copper and tin in the six types of copper ware. Due to the underdevelopment of science and technology, ancient craftsmen were unable to sample and analyze the molten bronze alloy. Therefore, the ratio of gold to tin refers to the proportion before casting and during cutting, rather than the proportion of components after casting. During the melting process, copper and tin undergo certain oxidation reactions, and the rate of tin oxidation is particularly fast. Therefore, the composition ratio of bronze after cooling is difficult to match when cutting.
The bronze alloy proportioning technology in ancient China is very complex, reflecting the continuous development and improvement of bronze casting technology, and reflecting the dual pursuit of metal hardness and toughness. During the Shang and Zhou dynasties, the alloy ratio of bronze ware was very particular, and there were significant differences in the alloy changes between early and late bronze ware. The containers in the early Shang Dynasty were mainly tin bronze, which had an increase in tin content compared to the Xia Dynasty, but still had a moderate content; In the late Shang Dynasty, containers with moderate to high tin content were mostly used. In addition, from the small amount of lead copper ware during this period, it can be seen that the lead content is mostly high. The main component of weapons in the late Shang Dynasty was tin bronze. As for various production tools during this period, there were few made of tin bronze anymore, and even if there were, their tin content was relatively high. During the Western Zhou Dynasty, the tin content of tin bronze was most common in the medium range, while lead bronze was relatively rare. A few lead bronze vessels also had a higher lead content. In addition, tin bronze already accounted for a certain proportion of bronze containers during this period.
In the Bronze Age, since only copper, tin, lead, gold, silver and other metals were mastered, there was no new metal that could surpass the unique superior properties of bronze when preparing alloys, so people could only constantly seek different copper tin ratios to cast various bronzes.
Leading supplier of bronze wares with high-level alloy
Sculpmart is a professional bronze art and bronze wares manufacturer providing Chinese Bronze Handcraft arts which will allow you to have a chance to own a masterpiece of Chinese bronze sculptures. If you like, you may choose the style to customize, send us the image and design, our craftsman will reproduce and cast a perfect bronze ware for you.
Please contact us if you need.
