On March 1, 1994, the world-famous "Eighth Wonder of the World" - Qin Shihuang's Terracotta Warriors and Horses Pit No. 2 officially began to be excavated. This is one of the great archaeological discoveries of this century.
In the No. 2 figurine pit, copper spears, copper crossbows, copper arrowheads, broken swords, etc. were also unearthed. Among them, a batch of bronze swords were also found, with a length of 86 centimeters, and eight inscriptions on the sword body. An edge. Archaeologists used vernier calipers to measure and found that the error of these eight edges was less than a hair. This is true for the 19 bronze swords that have been unearthed. These bronze swords have dense internal structure, bright and smooth blades, fine grinding patterns on the blades, and no interlacing textures. They have been sleeping under the loess for more than 2,000 years. When they were unearthed, they were as bright as new and extremely sharp. After testing, scientific researchers found that there was a 10-micron-thick layer of chromium salt compounds on the surface of the sword. This discovery immediately caused a sensation in the world, because this chromium salt oxidation treatment method is an advanced technology that only appeared in modern times. Germany invented and applied for patents in 1937 and the United States in 1950.
While cleaning the first passage of Pit No. 1, archaeologists found that a bronze sword was bent by a pottery figurine weighing 150 kilograms. The bending degree exceeded 45 degrees. When people After removing the pottery figurines, a surprising miracle occurred: the narrow and thin bronze sword rebounded straight in an instant and recovered naturally. The "morphological memory alloy" dreamed of by contemporary metallurgists actually appeared in ancient tombs more than 2,000 years ago.
In fact, the method of chromium salt oxidation treatment was by no means an invention of the Qin Shihuang era. As early as the Spring and Autumn Period and the Warring States Period, the Chinese had mastered this advanced technology.
During the Five Hegemons period of the Spring and Autumn Period, King Gou Jian of Yue "suffered hardship" and defeated King Wu Fu Chai in one fell swoop, performing the last scene of the Spring and Autumn Hegemony in history. As the years passed, this thrilling war fell silently into the long scrolls of history, and the busy descendants almost forgot about it.
However, when an archaeological team was excavating the ancient tombs of the Spring and Autumn Period, they accidentally discovered a long sword covered with mud. A line of ancient seal characters on the sword - "King Gou Jian of Yue's own sword" jumped into people's eyes. . This major archaeological discovery immediately caused a sensation across the country, but the even more sensational news came from the scientific research report on the ancient sword. What first attracted the researchers' attention was why this ancient sword had not rusted after being buried underground for more than two thousand years. Why is it still radiating cold light and extremely sharp? Through further research, it was found that the reason why the "Yue King Goujian Sword" has been stainless for thousands of years is that the sword body is plated with a layer of metal containing chromium. As we all know, chromium is an extremely corrosion-resistant rare metal. The chromium content in earth rocks is very low, and it is very difficult to extract it. Furthermore, chromium is a high-temperature resistant metal with a melting point of approximately 4000°C.
There have been too many secrets in Chinese civilization. Who could have imagined that the scientific inventions of the 1950s would have appeared more than 200 years ago? Who could have imagined that the long swords wielded by Qin Shihuang's soldiers were actually masterpieces that had not yet been invented by modern science. The question is, after discovery, what attitude do we use to explain this extraordinary phenomenon of premature technological maturity? We really don't want to see some people explain it by "accidental", it should have a more specific explanation. If the above facts are true (at least the chromium salt oxidation treatment is not false), then we will ask: What is the origin of their technology.