Bronze swords began in Shang Dynasty. At that time, its leaves were generally short, shaped like willow leaves, and its production was relatively rough. After the late Spring and Autumn Period, the production of bronze swords reached maturity, and the story of "Gou Jian, the King of Yue" happened in this period. At this time, bronze swords are generally lengthened to 50 or 60 centimeters.
A bronze sword is mainly composed of the body and the handle, and the so-called "handle" is the handle. There is also a raised partition between the hilt and the body, which is called "grid". The more exquisite bronze sword has some decorations on the "lattice" to show the identity and status of the user. These decorations are usually made of jade, so this kind of sword is also called "Jade Sword". After the Western Han Dynasty, bronze weapons were replaced by iron weapons, and bronze swords gradually withdrew from the historical stage.
In ancient China, the bronze blade was very thin, brittle and easily broken, so it was only suitable for stabbing but not splitting, so people called it "straight soldier" at that time. In the western world at the same time as Qin Shihuang, there is no bronze sword that can exceed 30 cm, but the ancient bronze swords found in the Terracotta Warriors and Horses are all nearly 1 meter long, which is striking.
Bronze sword-the perfect combination of sharpness and flexibility 1965. Archaeologists found a bronze sword in the tomb of the Warring States Period at Wangshan, Jiangling, Hubei. This sword, which is 55.6 cm long and 5 cm wide, emerges with beautiful streamline. After wiping off the floating dust, the black diamond pattern of the sword body shines like starlight, and the lattice of the sword is inlaid with moire and animal face pattern, with turquoise and extremely rare blue glass. The hilt of the sword is engraved with eight bird seal inscriptions of "Goujian Sword of the King of Yue".
Although it has been buried underground for more than two thousand years, it will never rust when unearthed, and it will be cold and shiny, just like the feeling of water overflowing and thawing! Scientists found that the middle ridge and two blades of the sword were made of two different bronzes. The blade is hard and sharp, but the inner core is extremely tough.
This just proves that the legendary "compound sword" does exist. The ridge with good toughness is made of low-tin bronze, and the blade with high strength and hardness is made of high-tin bronze, and then the two are connected into one by a very clever tenon-mortise structure.
As we all know, bronze is an alloy of copper and tin or copper and tin and lead (also known as "three gold" by the ancients), in which tin is the main factor affecting the hardness of the alloy. High tin content makes it brittle and hard, while low tin content makes it flexible.
As far as casting sword is concerned, if the sword is hard and sharp, it is necessary to increase the tin content; If the sword is required to be flexible and not easily broken, the tin content must be reduced. This is a difficult technology to solve. Without excellent technology, it is difficult to cast a sharp bronze sword that is not easy to break.
In the bronze age of other ancient civilizations in the world, short swords prevailed, but long swords over 50 cm were rare, such as ancient Egypt, the two river basins, Greece and Rome.
On the grasslands of Eurasia, from the northern shore of the Black Sea to the Mongolian grasslands, the so-called "skeat-style" bronze swords (commonly known as "Northern China Bronze Sword" by French scholars) are all short swords, generally about 30 cm long. So, how was this long sword cast? "Kao Gong Ji" recorded only one sentence: "yellow, white, hard and tough". Yellow is bronze and white is tin. How can you mix? What is the best ratio? I'm afraid this is the real secret of the sword-casting master.
It was by skillfully controlling the tin content in different parts of the sword body that the master of sword casting in the Eastern Zhou Dynasty made a bronze composite sword with both rigidity and flexibility. Unfortunately, even if we can analyze their proportions today, we have no choice but to completely copy that exquisite craft. With the development of casting technology, the length of bronze swords has been increasing. By the late Warring States period, swords about 70 cm long were not common.
At the end of the Warring States period, bronze swords 80-90 cm long appeared. If you have the opportunity to visit the Terracotta Warriors and Horses of the First Qin Mausoleum in Shaanxi, you can see those long swords with dark and sharp surfaces, which is unique in the world. Ou Yezi, Ganjiang and Mo Xie, these swordsmen left too many secrets. Today, the surface treatment technology of bronze swords spread all over the world is still an unsolved mystery.
You may have seen that the bronze sword unearthed during the Warring States period had a dark green and gray dark black surface, which was not the result of contact with air and corrosion. This surface, after it was made, has achieved such an effect. Although it has been buried underground for 2000 years, it has not changed gradually and there are no traces of rust.
What is certain is that the surface of the sword has undergone some special treatments, so that the body of the sword is well covered and the surface has a high hardness (laboratory tests reveal that the surface hardness of the sword is much higher than that of the deep layer, and far exceeds that of the general copper sword). Scholars speculate that these swords may have undergone special surface treatment after casting, so that the surface of the swords is naturally covered with a layer, which is extremely hard and does not rust, which not only improves the performance obviously, but also plays an anti-corrosion role.
But the specific method cannot be determined. The detection and analysis of some bronze swords reveal that the surface structure contains something called trivalent chromium compound, but the detection and analysis of other bronze swords have different results. Their surface is a polymer coating formed by soil paint and silicon dioxide, that is, raw paint film. What makes these swords cold after thousands of years is still a mystery.
Thoroughly tempered. For two thousand years, this bronze sword has been intact. The bronze sword unearthed in the second pit of Qin Shihuang's mausoleum is 86 cm long and has eight facets, which are extremely symmetrical and balanced. They have been unearthed from the ground for 2000 years, but they are as clean as new, without corrosion or rust. Through modern scientific methods, the surface of these bronze swords is covered with an oxide film with a thickness of about 10 micron, which contains 2% chromium. This discovery immediately shocked the world, because this kind of salt oxidation treatment is an advanced technology that was mastered only in modern times.
It is said that Germany invented it and applied for a patent in 1937, and the United States invented it in 1950, which can only be realized under a set of complicated equipment and technological processes. The forging degree of Qin people is unimaginable. What is particularly commendable is that the toughness of these bronze swords is amazing. There is a sword, which was bent by a clay figurine weighing 150 Jin, and the twists and turns exceeded 45 degrees.
At the moment when the pottery figurines were taken out, the spectacle happened, and the bronze sword bounced straight and recovered naturally. This exquisite sword casting skill is amazing, but I don't know why.
Fu Cha's sword, in the late Spring and Autumn Period (Fu Cha reigned for 22 years, 495-473 BC), has a total length of 58.3 cm, a body width of 5 cm, a grid width of 5.5 cm and a hilt length of 9.4 cm.
(1) Fan-making: The sword fan is molded with clay, then put into a kiln to dry with fire, and then trimmed. The model is based on the shape design of bronze sword, and whether the shape of bronze sword can meet the design requirements, neat and harmonious, symmetrical and elegant depends on whether the model is fine or not.
(2) Adjustment: The casting sword is made of bronze, which is an alloy of copper and tin or copper and tin and lead. Dosage refers to the proportion of components in bronze alloy, which was written as "gas" in ancient times. Before smelting bronze, copper, tin or copper, tin, lead and other raw materials must be mixed according to reasonable proportioning rules, which is called mediation.
This is the key link to determine the performance of bronze sword. "Gold has six ranks" recorded in "Flower King Gong Ji": the achievement of attacking gold indicates the composition ratio of six types of bronzes, of which the fourth category is: the big blade is the sword; Two thirds of its gold and tin are in one place, that is, bronze alloy is divided into four parts, copper (gold) accounts for three parts (75%) and tin accounts for one part (25%).
The "Liu Qi" in "Flower King Gong Ji" only shows the two most important components in bronze alloy-copper and tin, and copper often contains a small amount of lead and other elements (iron, zinc, etc. ). Therefore, Liu Qi's copper-tin ratio method generally represents the proportion of copper and other non-copper elements in bronze alloys.
The researchers tested the mechanical properties and hardness of this copper sword, which proved that it had good strength and hardness.
(3) smelting: after the raw materials are prepared, they are put into a crucible for smelting. The goal of smelting is to melt copper, tin, lead and other raw materials into liquid, and at the same time further remove impurities contained in the raw materials, such as charcoal attached to the raw materials, and other metal elements such as oxides, sulfides and iron contained in the raw materials, so as to make the alloy pure.
"Flower King Gong Ji" has a detailed description of this: where gold is cast, Suk Kim is exhausted, followed by yellow and white; Black pollution gas is produced by burning hydrocarbons such as charcoal and branches attached to raw materials. The yellow-white gas is mainly produced by melting tin with low melting point first.
(4) Casting: The molten bronze liquid is poured into the sword mold, and once cooled and solidified, a bronze sword is formed.
(5) Machining: The bronze sword cast by Fan is only a blank. After the casting fan is removed, the following trimming treatment must be carried out: scraping, trying to be nominally flat and smooth; Decoration, such as embedding colored glass and turquoise in the cast pattern groove, or embedding red copper wire, gold wire and silver wire in a staggered way, or even further carving patterns on the device surface; Install accessories to complete the sword; Sharpen the blade. Don't forget to quench. Otherwise, the cast "sword" will be like the sword of ancient Rome, with a stab, a straight step and continuous use.
(Note: The perfect bronze sword casting technology at that time has been lost to this day)