In fact, this is still a mystery. This sword has been buried for more than 2,000 years and is still extremely sharp. Records at that time said: "When the sword was taken out of the sheath, it shone with cold light. There was no rust, and the blade was thin and sharp. I tried it on paper. More than twenty layers were broken in one stroke. "But the question that arises is: why has it not rusted over thousands of years? In December 1977, experts from the Electrostatic Accelerator Laboratory of Fudan University in Shanghai, together with the activation analysis group of the Shanghai Institute of Nuclear Research, Chinese Academy of Sciences, used proton Accurate data sheet for bronze alloy distribution ratios. The main components of Goujian Sword of Yue King are bronze alloy composed of copper, tin and a small amount of aluminum, iron, nickel and sulfur. The black diamond pattern on the sword body is vulcanized, and the level of precision grinding of the sword blade is comparable to modern products produced on precision grinders. For example, the tail of the sword is a cone base, and the base is hollow and has an extremely There are 11 regular concentric circles with an interval of only 0.2 mm, and there is a thin rope pattern in the middle of the circle. This is something that cannot be achieved with modern lathe technology. The most noteworthy one is the conclusion of "vulcanization treatment". Simply put, "vulcanization treatment" is to dilute some substances and wrap them on the surface of the object. Scholars believe that the sword of King Goujian of Yue was treated with copper sulfide, which could prevent rust and maintain the beauty of the pattern. But later, many businesses and individuals who imitated the "King of Yue Goujian Sword" discovered after countless comparisons that the closest thing to the original "paste" of the "King of Yue Goujian Sword" was only chromium sulfide, not copper sulfide. This raises a question: Did the Chinese in the Spring and Autumn Period master the "vulcanization treatment" technology? It is said that "chromium sulfide" was invented in Germany in 1937 and the United States in 1950, and was patented. In fact, incredible technological elements like this are not isolated in China. Yuan Zhongyi's "Research on the Terracotta Warriors and Horses from the Mausoleum of the First Emperor of Qin" has this sentence: "A bronze sword in the eleventh hole in T2 of the Terracotta Warriors and Horses Pit No. 1 was bent because it was pressed by the fragments of the pottery warriors when it was unearthed. After the fragments of the pottery warriors were removed, The sword immediately rebounded and returned to straightness. "This involves the term "memory metal", also known as shape memory alloy. This technology appeared in the world of materials science in the 1970s.