Carbon fiber is hailed as the "black gold" of industry, characterized by its light weight, high specific strength, high specific stiffness, high-temperature resistance, and corrosion resistance. It has been widely used in "national heavy equipment" such as launch vehicles, satellite space stations, large aircraft, and large ships.

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The world's first! Carbon fiber subway train is here

On June 26th, the world's first carbon fiber subway train for commercial operation, "CETROVO 1.0 Carbon Star Express," was officially launched in Qingdao, Shandong.

This train is 11% lighter than traditional subway vehicles, with significant advantages such as being lighter and more energy-efficient, leading the way for a new green upgrade of subway trains.

Traditional subway vehicles mainly use metal materials such as steel and aluminum alloys, which are limited by the material properties and face weight reduction bottlenecks. Carbon fiber, known as the "king of new materials," has the advantages of being lightweight, high-strength, fatigue-resistant, and corrosion-resistant. Its strength is more than five times that of steel, but its weight is less than a quarter of steel, making it an excellent material for the lightweight construction of rail vehicles.The vehicle's main load-bearing structures, such as the body and the steering frame, are made of carbon fiber composite materials, achieving a new upgrade in vehicle performance. It has the technical advantages of being lighter and more energy-efficient, stronger, more adaptable to the environment, and having lower operational and maintenance costs throughout its life cycle.

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Compared to traditional metal subway vehicles, the carbon fiber subway vehicle has a 25% reduction in body weight, a 50% reduction in steering frame weight, and an approximate 11% reduction in the total weight of the vehicle. The operational energy consumption is reduced by 7%, and each train can reduce carbon dioxide emissions by about 130 tons per year, equivalent to planting trees and afforestation of 101 acres.

The carbon fiber subway train has a top speed of 140 kilometers per hour, which is a significant increase compared to the traditional subway speed of 90 kilometers per hour. Currently, the carbon fiber subway train has completed the in-factory type tests. According to the plan, it will be put into passenger demonstration operation on the Qingdao Metro Line 1 within this year.

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Can carbon fiber also be used for admission letters?

In 2024, Beijing University of Chemical Technology used carbon fiber composite materials to create admission letters, which are only 0.2mm thick and can display color changes when viewed from different angles under sunlight, showcasing the beauty of art and science!Beijing University of Chemical Technology's research team has continuously carried out research and development, applying the previously achieved domestic aerospace-grade carbon fiber specialty composite materials and high-quality autoclave curing technology for overall molding. They have made breakthroughs in the technology for releasing internal stress and controlling flatness of carbon fiber composite materials, surface UV printing technology, hot stamping process technology, and color printing technology for building patterns, ultimately achieving the mass production of "carbon fiber admission letters."

What is the most feared by carbon fiber materials?

When the sharp end of an axe strikes the carbon fiber composite material board, the sturdy board is surprisingly pierced and broken by the sharp end of the axe. Why has the carbon fiber composite material board, which has always been considered very strong and tough, suddenly become vulnerable?This is because when a solid carbon fiber composite board encounters an impact force on its surface, the interwoven carbon fiber strands within it can evenly distribute the force received without causing rupture. However, when a carbon fiber composite board encounters puncture by a sharp object, the immense impact force is concentrated at a single point, and the sharp tip can easily penetrate the gaps between the interwoven carbon fiber strands within, causing the solid carbon fiber composite board to be punctured.

Therefore, carbon fiber composite materials are most vulnerable to puncture by sharp objects; they have excellent resistance to the impact of blunt objects, but their ability to withstand puncture by sharp objects is quite poor.

Thus, in our daily lives, we should understand the characteristic of carbon fiber composite materials that they resist tension but not puncture, and avoid exposing carbon fiber products to sharp pebbles or pointed objects to prevent rupture.