Where did Qin Shihuang's high-tech weapons come from?

Although later generations have different opinions about Qin Shihuang, his position is undeniable. He unified the six countries, abolished the enfeoffment system, replaced it with the county system, with the same book and the same rail, unified measurement, built the Great Wall of Wan Li, opened up the southwest, and established a national model. These great achievements are enough to be told through the ages. In his legendary life, he also left many mysteries, including why his mausoleum was not destroyed for thousands of years and the real cause of his death. Today we are going to discuss the magical high-tech inventions around him, which are far beyond his historical era, and people have to doubt whether they really exist. Gods Help him.

A sword made of memory alloy more than 2000 years ago.

Why can the soldiers of the Qin dynasty be brave and invincible with one enemy and ten? The problem is the weapon. The late bronze sword is as sharp as mud and invincible. However, all the swordsmen were buried alive by Qin Shihuang, and Qin Jun's weapon secret was taken to the grave forever.

1994 March 1, which is world-famous? The eighth wonder of the world? The excavation of the second pit of the Terracotta Warriors and Horses of Qin Shihuang officially began. Many bronze swords, 86 cm long, were found in the No.2 pit. There are eight inspection surfaces on the sword body. Archaeologists measured with vernier calipers and found that the errors of these eight sides were less than a hair. There are 19 bronze swords unearthed.

These bronze swords have compact internal structure, smooth blades, fine grinding lines and no staggered textures. They have been sleeping in the loess for more than two thousand years, and they are still as bright as new when unearthed, and their blades are very sharp, and they can cut through twelve newspapers with one sword. Experts use modern scientific methods to detect and analyze, and the surface of these bronze swords is actually covered with an oxide film about 10 micron thick, which contains 2% chromium.

As we all know, chromium is a rare metal with high corrosion resistance. The content of chromium in earth rocks is very low, so it is difficult to extract. Furthermore, chromium is a high-temperature resistant metal, and its melting point is around 4000℃. Only 1937 in Germany and 1950 in America were invented and patented one after another. Who plated this metal on the sword more than 2000 years ago by what method?

When the archaeologists were cleaning the first hole of the No.1 pit, they found that a bronze sword was bent by a clay figurine of150kg, and the bending degree exceeded 45 degrees. When people removed the clay figurine, an amazing miracle appeared: the narrow and thin bronze sword bounced up instantly and recovered naturally. The dream of contemporary metallurgists? Shape memory alloy? It actually appeared in an ancient tomb more than 2,000 years ago. Does it sound funny?