China still needs breakthroughs in the technology of large-scale aluminum extrusion equipment.

The research, development and manufacturing of new high-speed trains, vessels and large aircraft in China rely heavily on a wide range of high-end advanced materials, among which the production of large aluminum profiles stands as an indispensable core link. Therefore, it is an extremely urgent task for China’s equipment manufacturing industry to independently develop high-tech large aluminum extrusion and stretch straightening equipment as soon as possible, and accelerate the popularization of domestically manufactured advanced production equipment for large aluminum profiles.

Large aluminum profiles generally refer to aluminum products with a width exceeding 800 mm, a circumscribed circle diameter over 250 mm and a delivery length longer than 12 meters. Featuring complex cross-sections and a maximum length of 60 meters, large aluminum profiles integrate multiple functional attributes and can achieve precision equivalent to that of conventionally machined components. As critical structural materials, they are applied to core parts of machinery and equipment.

A single large aluminum profile can replace wide thin-walled aluminum assemblies previously fabricated by joining two or more separate profiles. This optimizes the structural design of mechanical parts and delivers superior surface finish. Meanwhile, the production of large aluminum profiles improves extrusion productivity and cuts manufacturing costs. Without large aluminum profiles as core supporting materials, the vision of "Made in China" for new high-speed trains, ships and large aircraft would remain nothing but empty talk.

More importantly, large aluminum profiles are not merely essential materials for manufacturing new high-speed trains, ships and large aircraft; they are also vital supplies desperately required across all sectors amid China’s rapid economic expansion. They are widely used in the production of modern transport equipment including subways and light rails, the manufacture of modern armaments for national defense construction, as well as the development of aerospace and other industries.

Driven by the expansion of China’s subway, high-speed rail, urban light rail and aerospace sectors in recent years, demand for large thin-walled, wide-format, high-precision aluminum alloy profiles with complex cross-sections has surged rapidly. Such profiles are used for aircraft panels, high-speed train car bodies, subway and light rail carriages, maglev train bodies, containers and ship hull panels.

During the Eleventh Five-Year Plan period, the state invested RMB 200 billion in subway construction in major domestic cities, with all newly manufactured subway carriages to be constructed from extra-large aluminum alloy profiles. Relevant forecasts indicate that China’s annual demand for extra-large aluminum and aluminum alloy profiles will exceed 150,000 tons over the next five years, with imported products priced at approximately USD 10,000 per ton.

Extrusion presses come in various types, yet the international industry defines presses with a capacity above 50 MN as large extrusion presses, and those above 80 MN as heavy-duty extrusion presses. At present, the total global installed quantity of domestic and foreign large extrusion presses does not exceed 40 units.

Most large extrusion presses deployed overseas were manufactured prior to the 1970s and are mostly outdated hydraulic water presses. In recent years, the United States, Germany, Japan, South Korea and other countries have added four to five new large extrusion presses.

China currently operates seven completed production lines for large aluminum profiles, with another five large aluminum extrusion press lines under construction. More than ten additional large extrusion press production lines will be built within the next five years.

Large extrusion presses boast enormous potential market demand in China, while global demand is also on the rise. Nations including Southeast Asian countries and India are still in the initial stage of developing large extrusion equipment, yet it is projected that multiple large extrusion production lines will be put into operation within a decade.

Developed countries have long attached great importance to the R&D of large aluminum extrusion equipment, with numerous specialized technical research centers established successively. Well-known institutions include Germany’s BCTiin Extrusion Technology Center, the Kentucky Extrusion Technology Center in the United States, and Hydro’s Extrusion Technology & Engineering Research Center in the United Kingdom.

China started relatively late in the research and development of large aluminum extrusion technology and supporting equipment. Its research tools, methodologies, manpower and financial investment all lag behind developed economies. In this field, China National Heavy Machinery Research Institute (Xi’an Heavy Machinery Research Institute) and Taiyuan Heavy Industry Co., Ltd. take the leading position domestically.

Starting in 1999, China National Heavy Machinery Research Institute developed China’s first 10,000-ton oil-driven extrusion production line, which was officially commissioned on July 1, 2002. In 2003, the institute launched the development of a 125 MN oil-driven double-action aluminum extrusion production line, which has now completed installation and commissioning, marking a major breakthrough for China in the technical development and new product research of large aluminum profiles.

To date, the institute has designed, developed and manufactured over 30 copper and aluminum extrusion production lines ranging from 5 MN to 125 MN. Its self-developed 125 MN double-action aluminum extrusion press ranks as the world’s largest oil pump direct-drive aluminum extruder, while the 40 MN double-action copper extrusion production line is Asia’s largest copper extrusion facility.

In addition, the institute has developed downstream processing equipment matching 55 MN, 60 MN, 100 MN and 125 MN aluminum extrusion lines, and a 150 MN aluminum extrusion production line is currently under development.