On October 8, workers stepped up production inside the workshops of Southwest Aluminum. (Photo/Chongqing Daily)
Chongqing - Southwest Aluminum prepared a fresh batch of aviation-grade aluminum alloy forgings for shipment on October 25, supplying components for China’s C919, a home-grown passenger jet seeking a place in the global commercial aircraft market.
As a leading manufacturing enterprise in Chongqing, the firm has cracked numerous R&D bottlenecks for aviation aluminum materials in recent years. 13 categories of its self-developed key aluminum alloys are mass-applied to core C919 parts, including nose window frames and wings.
To date, the firm has supplied nearly 2,000 tons of high-performance aluminum materials and over a thousand products for the C919. Its stable mass-delivery capacity and micron-level machining accuracy underpin the material foundation for the safe flight of China’s large home-built airliner.
One forging demonstrates technical strength
A C919 cabin window frame component on display at Southwest Aluminum shows how demanding aircraft manufacturing can be. The aluminum-alloy forging weighs about 1.5 kilograms and has a web section just 3.5 millimeters thick, requiring far greater precision than ordinary industrial aluminum products.
“Critical safety components for passenger aircraft must withstand extreme conditions such as high-altitude air pressure and drastic temperature swings. Only two enterprises worldwide are capable of mass-producing them, and Southwest Aluminum is one,” a company R&D official said. This seemingly simple thin forging was long subject to foreign technological monopoly.
Back in 2019, as C919 development entered a critical phase, China encountered constraints from overseas suppliers of specialized aluminum materials for cabin windows.
The firm developed a domestic source of the aviation aluminum material in six months, reducing reliance on foreign suppliers amid technology restrictions and supply chain constraints. A dedicated research team refined alloy composition, forging procedures and forming techniques through repeated trials, taking the material from development through trial production to mass manufacturing.
Thousands of trials fill domestic technical gaps
The breakthrough followed years of research, with Southwest Aluminum beginning work on high-end aviation aluminum materials in 2005.
Aviation aluminum imposes exacting standards for strength, toughness, corrosion resistance and fatigue performance. To resolve bottlenecks in material property matching and precision forming, its R&D team worked in labs and workshops through iterative trials and process refinement.
To shore up weak links across the industrial chain, researchers completed more than 1,000 sample analyses and process verification tests. After repeated parameter adjustments and revisions, core technical hurdles were overcome. In 2015, Southwest Aluminum realized industrial-scale mass production covering product thicknesses from 6 mm to 203 mm.
This milestone filled a domestic technical gap and supplied core materials for major national projects including China’s space station and the C919 jetliner.
Southwest Aluminum has secured more than 20 key aviation-aluminum technologies such as super-large-size casting and precision isothermal forging.
Its aluminum materials match global top-tier performance and have obtained certifications from leading aerospace players including Boeing, Airbus, Safran and Chongqing Municipal People's Government and the Commercial Aircraft Corporation of China (COMAC). It is also the first domestic enterprise granted COMAC airworthiness certification to supply aluminum alloys for the C919.
The firm now has 13 aviation-grade materials on COMAC’s supplier list, giving the C919 a domestically controlled supply of key aluminum materials for nose window frames, landing gear wheel hubs and wings. The company’s total aluminum output rose 10 percent year on year in the first three quarters, while its capacity for high-end aviation materials continued to expand.
Technology transfer boosts manufacturing upgrading
Drawing on stringent process standards honed for aerospace supply, Southwest Aluminum is spinning off high-end aluminum technologies to fuel multi-sector industrial upgrading across Chongqing.
“Beyond aluminum-alloy technical breakthroughs, we aim to drive overall upgrading of local new-material industrial chains and foster coordinated development of upstream and downstream partners,” said a Southwest Aluminum representative.
The enterprise has expanded material applications into emerging sectors such as new-energy vehicles and rail transit, translating material strengths into industrial advantages.
For intelligent connected new-energy vehicles, its self-developed premium automotive aluminum sheets have passed certification by Seres and are mass-produced for all AITO vehicle models. They are used in key auto parts including body panels, high-strength structural components and lightweight battery trays.
These advanced aluminum sheets make vehicles substantially lighter than conventional steel, reducing energy consumption while meeting body rigidity and crash safety requirements.
Southwest Aluminum has built a large-scale production base with an annual capacity of 100,000 tons of premium automotive aluminum sheets, delivering stable, high-quality and cost-effective material supplies for local automakers.