The bronze swords unearthed from the pit of Qin Terracotta Warriors and Horses were cast with two fans, the body and handle were cast once, and the lattice was cast separately. Regular blade ridge, fine structure and no sand holes. After grinding, polishing and other fine processing, the sword body is bright and flat, and the blade is sharp. After testing, its smoothness is between 6-8 flowers. The most striking thing is that more than a dozen bronze swords unearthed in the pit of Qin terracotta warriors and horses have been buried underground for more than 2000 years, and they have not rusted so far, and they are as clean as new. After testing and analysis, it is found that there is a dense chromium salt oxide layer on the surface of bronze sword, and the thickness is 10 ~ 15 micron. This advanced technology of treating watches with chromate to enhance the anti-corrosion and anti-rust ability of bronze or other non-ferrous metals was invented by Germany 1937 and the United States 1950, and was listed as a patent. As early as more than 2,000 years ago, China had created a similar craft in the Qin Dynasty, and achieved success in bronze weapons for the first time. This is a miracle in the world metallurgical history. Today, we can't know the specific process and method of chromium plating on weapons. Through analysis and inspection, the alloy composition of bronze sword contains copper 73-76%, tin 18-2 1%, lead 0. 17-2. 18% and other trace rare metal elements. The requirement of Kao Gongji for the proportion of copper and tin in the sword is "three points of gold and one point of tin". The ratio of copper and tin in the sword is 3.4: 1 ~ 4: 1, which is basically consistent with the records in the examination. The sword made according to this ratio has certain hardness and toughness and is not easy to break. Because of the different tin content in bronze, it has a direct impact on the hardness of castings. The tin content of bronze swords unearthed from Qin terracotta warriors pit is as high as 18 ~ 2 1%. After determination, the hardness is HRbl06 degrees, which is about equivalent to the hardness of medium carbon steel after quenching and tempering, ensuring its hard and sharp combat effectiveness. The bronze cymbals unearthed from the pit of Qin terracotta warriors and horses were cast separately from the collar, that is, the collar was made into a prefabricated part first, and then the head was cast together. After the collar was cast, the stubble at the joint was still clearly visible without further grinding. The leading processing technology is fine, and the polished surface is smooth and flat. After testing, the surface finish is 6 ~ 8 flowers. In particular, the surface of the collar, like the bronze sword, has also been oxidized by chromium salt. The minimum difference between the three ridges of the bronze arrow is 0.02 mm, the length is almost the same, and the contour error of the three sides is less than 0.15 mm. The sharp edge of the countersunk head adopts a streamlined three-dimensional space curve, which miraculously coincides with the contour line of the modern pistol warhead after magnification of 24 times. It shows that the production models and styles of weapons in Qin dynasty have been standardized, serialized and standardized. It shows the accuracy of manufacturing dimensions and superb technical level. Because of its small size and large demand, samarium cannot be recovered once it is launched. Therefore, since the Shang Dynasty, the casting of bronze arrows has developed into a multi-tool model on the basis of one model to improve production efficiency. Therefore, the casting of bronze arrows in the Qin Shihuang era should also be double-sided multi-cavity mold casting, and several arrows can be cast at a time. In addition, it is found that the alloy composition of bronze samarium contains 78.88-88% of copper,11.10/7% of lead and 3-7.7 1%. In Flower King Gong Ji, the collocation principle of copper and tin in the reverse arrow is "five cents for gold and two cents for tin". The measured ratio of copper, bismuth, copper and tin is 5.6: 1, which is quite different from the inspection records. However, besides tin, copper samarium also contains lead, which, like tin, can lower the melting point, improve the hardness of castings and improve the casting performance. This shows that people have a deep understanding of the relationship between alloy composition, properties and uses in long-term bronze smelting and casting practice. According to the different uses of different weapons, different alloy ratios can be made. Long weapons, such as copper ge, copper spear and copper beryllium, are all cast by double mold method, and the mold core is also used for spear epiphysis and hollow spear body. The surface treatment of these three weapons is also very fine, and the smoothness is similar to that of bronze swords. It is worth noting that both sides of copper and beryllium have natural irregular natural patterns. These patterns are neither cast nor engraved, but invisible and integrated with the metallographic structure on the surface of the device. This looming pattern formation process has also become one of the mysteries of Qin figurines. Some people speculate that it, like Yue and Wu, may be vulcanized. The patterns of sword and hair are relatively regular, which is different from the irregular patterns of copper and beryllium in Qin terracotta warriors and horses, and the technology is also different. With the progress of science and technology and the deepening of research, I believe this mystery will be uncovered one day. For the alloy composition of germanium, spear and halberd, it is found that spear contains 79.42% copper, 0.75% lead and the balance tin. The ratio of copper to tin is 4: 1, which basically conforms to the record that "four parts of gold and tin occupy one place, which is called the gas of the grid". Because Pueraria lobata and Mao are stab soldiers, their tin content is high and their Brinell hardness is above 100. Only when the alloy proportion is appropriate can the good performance of sharp edge be achieved.
The famous bronze sword in history:
Tenth, exquisite and elegant sword, invisible sword.
Ninth, noble and unparalleled sword, pure gentleman = pure hook white Jian Qing.
Eighth, the sword of courage, the black sword of fish intestines
Seventh \ sixth, the sword of love, Lieutenant \ Mo Xie Silver Sword \ Purple Sword.
Fifth, the sword of honesty and purity, the sword of seven-star dragon in white.
Fourth, the sword of Wei Dao, Ron Artest = Ron Artest soft sword.
Third, Tao's sword, Chi Xiao's iron sword.
Second, the sword of the benevolent, the black sword of Zhan Lu.
First, the sword of the Holy Way, Jin Jian, Xuanyuan Sword
Bronze swords were used during the Spring and Autumn Period and the Warring States Period.