According to the Science and Technology Daily report on June 26th, the world's first commercialized carbon fiber subway train, "CETROVO 1.0 Carbon Star Express," was officially released in Qingdao. The train is 11% lighter than traditional subway vehicles, leading to a brand new green upgrade for subway trains.
The application of carbon fiber materials in the transportation industry is particularly eye-catching. It not only brings the advantages of lightweight and high strength to rail transit trains but also promotes the green and sustainable development of the rail transit industry, injecting new vitality into the future development of urban rail transit.
Let's step into the world of carbon fiber subway trains together and explore the mysteries and charm behind this innovative technology!
What is carbon fiber?
Carbon fiber may sound a bit mysterious and high-tech, but in fact, it plays an increasingly important role in our daily lives. Simply put, carbon fiber is a new type of fiber material with a carbon content of more than 90%.Carbon fiber is like a super-strong "thread," but it is not an ordinary thread; it is composed of extremely fine beams of carbon atoms. Imagine a hair strand magnified thousands or even tens of thousands of times, if it were made of pure carbon, it would be like a carbon fiber.
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How is carbon fiber prepared?
The preparation of carbon fiber is like a wonderful "magic show." To obtain carbon fiber materials, it is necessary to go through a series of processes such as the preparation of fiber precursors, fiberization and pyrolysis, and high-temperature treatment.
The fiber precursor is the key to the preparation of carbon fiber and can use materials such as polyacrylonitrile, polyamide, viscose fiber, and natural fibers as raw materials. First, chemical reagents are used to dissolve substances such as polyacrylonitrile, and then the fiber precursor filaments are prepared through spinning, stretching, and other processes.
Next, through a series of chemical and physical treatments, impurities in the fiber precursor filaments are removed, internal defects in the fibers are eliminated, and the stability of the fibers is improved. Further high-temperature carbonization and graphitization treatments are carried out on the material under high-temperature conditions, allowing non-carbon elements in the fibers to gradually detach, thereby increasing the carbon content in the fibers.After these treatments, the arrangement of carbon atoms in the material will be more regular, and an internal graphite-like crystal structure will be formed. Finally, the carbon fiber after graphitization is subjected to a sizing process to improve its surface properties and further enhance the performance of the material.
For specific application requirements, the formed carbon fiber material can also be surface-modified, functionally decorated, or compounded with other materials for processing, ultimately producing carbon fiber products with specific shapes and properties.
What are the advantages of carbon fiber?
Carbon fiber not only has the basic characteristics of carbon materials but also has the excellent mechanical properties of fiber materials.
Firstly, carbon fiber is very light, with a density only one-fourth of that of steel. However, the tensile performance of carbon fiber is very excellent. The tensile strength of high-modulus carbon fiber is more than 6 times higher than that of steel, and the elastic modulus can also reach twice that of steel. Moreover, carbon fiber is particularly resistant to high temperatures and will not deform even in high-temperature environments.In addition, carbon fiber also has excellent corrosion resistance and electrical conductivity. Therefore, it has a wide range of applications in various fields such as construction and aerospace.
Carbon Fiber Metro Train
On June 26, 2024, the commercial carbon fiber metro train, jointly developed by CRRC Sifang Locomotive Co., Ltd. and Qingdao Metro Group, was officially released!
The main load-bearing structure of the train, including the body and bogie frame, is made of carbon fiber composite materials. Due to the low density and light weight of carbon fiber materials, the metro train is about 25% lighter than the traditional metro vehicles made of metal materials, the bogie frame is about 50% lighter, and the overall weight reduction of the train has reached 11%. The lightweight of the metro train makes its operating energy consumption lower.
According to calculations, compared with traditional metro vehicles, the operating energy consumption of the carbon fiber metro train can be reduced by 7%. Each train can reduce carbon dioxide emissions by about 130 tons per year, making a great contribution to energy saving and emission reduction. In addition, the high-strength carbon fiber materials enhance the structural strength and safety of the train.Aerospace Industry
The advantages of carbon fiber have made it shine in the aerospace field. Aircraft made with carbon fiber composite materials are lighter overall, thus having higher payload capacity, better fuel efficiency, and longer flight distances.
In addition, carbon fiber materials are also used to manufacture aircraft engine components. Due to their excellent heat resistance and corrosion resistance, they ensure the stable operation of the engine in extreme environments such as crossing the atmosphere.
Construction Industry
Carbon fiber composite materials, due to their outstanding mechanical properties and durability, are widely used in the reinforcement projects of bridges and roads. By pasting carbon fiber composite material layers, the load-bearing capacity and service life of bridges and roads can be effectively improved, reducing the frequency of maintenance and reconstruction.In addition, carbon fiber composite materials are also used to make protective covers and architectural decoration materials. Their lightweight and high-strength characteristics make the protective covers lighter and more robust, effectively protecting buildings and cultural relics from natural disasters and human damage.
Sports Equipment
Carbon fiber materials, with their lightweight, high-strength, and good impact resistance, are widely used in the manufacturing of sports equipment, providing us with a safer, more comfortable, and more efficient sports experience. They can be found in bicycles, golf clubs, snowboards, and more.
Carbon fiber is the preferred material in the high-end bicycle field. Compared with traditional metal materials, the weight of a carbon fiber frame can be reduced by about 30%. In addition, carbon fiber bicycles also have excellent shock absorption and stability, which can effectively reduce fatigue during long periods of riding. Moreover, carbon fiber snowboards have good impact resistance, which can reduce the risk of athletes being injured due to accidental collisions during skiing.
The birth of commercial carbon fiber subway trains marks a solid step forward for the rail transit industry in material innovation and green travel. It will not only bring a more efficient and safe travel experience but also promote the development of the entire rail transit industry towards a more environmentally friendly and sustainable direction. We have reason to believe that in the near future, this green, efficient, and safe subway train will become the main force of urban public transportation, leading us towards a more green and low-carbon future!