As an important part of the national transportation infrastructure, rail transit is valued for its large capacity, high efficiency, low carbon and environmental protection. With the acceleration of urbanization and the expansion of high-speed rail and urban rail networks, transportation rail aluminum profiles, relying on their lightweight, high strength, corrosion resistance and other advantages, have replaced traditional steel materials in many fields, becoming the core material for improving the operational efficiency and safety of rail transit vehicles, and promoting the high-quality development of the rail transit industry. The core demand of rail transit for materials is to balance “lightweight” and “high reliability”, and aluminum profiles perfectly meet this requirement. The density of aluminum is only 1/3 of that of steel, and using aluminum profiles in the manufacture of rail vehicle bodies can reduce the overall weight of the vehicle by 15%-20%, which not only reduces energy consumption and operating costs — especially for freight trains, it can also increase the loading capacity — but also reduces the wear of tracks and bogies, extending the service life of the entire rail system. At the same time, rail aluminum profiles have excellent mechanical properties: high-strength 7000 series aluminum alloys (such as 7005-T6, 7075-T7351) have a yield strength of more than 350MPa, which can meet the structural strength requirements of high-speed trains running at 350km/h; 5000 series aluminum alloys have excellent corrosion resistance, adapting to harsh operating environments such as coastal high humidity and cold areas. Transportation rail aluminum profiles have a wide range of applications, covering vehicle structures, interior and exterior components and track accessories. In terms of vehicle structure, aluminum profiles are used to manufacture body frames, roof panels, floor supports and wall panels, forming a lightweight and high-rigidity body structure — high-speed trains and modern subways basically adopt all-aluminum body designs, which not only improves operational efficiency but also enhances collision safety by absorbing collision energy through the deformation of aluminum profiles. In terms of interior and exterior components, aluminum profiles are used to make window frames, door frames, interior decorative panels and handrails: window and door frame profiles are designed with thermal insulation breaks to improve the thermal insulation performance of the carriage; interior decorative panels are lightweight, easy to clean and have a modern appearance, enhancing the passenger riding experience; handrails are corrosion-resistant and wear-resistant, ensuring long-term safe use. In terms of track accessories, aluminum profiles are used in pantographs, rail support brackets and electrical system components, relying on their good electrical conductivity and oxidation resistance to ensure the stable operation of the electrical system. In recent years, the rail aluminum profile industry has continuously achieved technological breakthroughs. In terms of material innovation, the deep improvement of 7000 series aluminum alloys and the engineering application of aluminum-lithium alloys have further improved the strength and lightweight level of profiles; in terms of surface treatment, micro-arc oxidation and anode oxidation composite processes have made the salt spray resistance of profiles reach more than 2000 hours, adapting to various harsh environments; in terms of manufacturing technology, high-precision extrusion equipment (maximum extrusion tonnage up to 36000 tons) can produce extra-large and complex cross-section profiles, and intelligent equipment such as industrial robots and digital twins have realized the full-process optimization of production, ensuring product quality stability. With the promotion of the “Belt and Road” initiative, Chinese rail transit technology and supporting aluminum profiles have been exported to Southeast Asia, Europe and other regions, opening up a broader international market for the rail aluminum profile industry.
