In aircraft manufacturing, forgings are the core components that determine the performance, reliability, lifespan, and economy of an aircraft. By weight, the forgings used in aircraft account for approximately 20% to 35% of the total weight of the aircraft's structure. The forgings in aircraft are mainly concentrated in three core areas: the fuselage structure, the landing gear system, and the aircraft engine. The specific distribution and types are as follows:
1. Fuselage structure forgings.
The fuselage is the foundation of the entire aircraft's structure, and its internal components such as frames, wing spars, and critical load-bearing components, as well as door frames and wing connection parts, are mostly made of titanium alloys, ultra-high-strength steels, nickel-based superalloys, or aluminum alloys to ensure sufficient strength and rigidity.
Fuselage components: including door frame, nose windshield frame, wing and fuselage connection parts, fuselage load-bearing frame, steering wheel shaft frame, etc.
Wings and tail wings: mainly providing lift and directional control, the key forgings include wing spars (main longitudinal load-bearing components), strakes, load-bearing beams, frame forgings, and wing ribs, etc.
2. Landing gear system forgings
The landing gear is the main supporting structure of the aircraft during takeoff, landing, and taxiing, and it withstands huge impact loads. Over 95% of modern aircraft landing gears are made of ultra-high-strength steel, and some may also use titanium alloys and aluminum alloys.
Main forgings: including main landing gear outer cylinder, piston rod, torsion arm, diagonal support, support, and rear support, etc.
3. Aircraft engine forgings
Forgings are widely used in aircraft engines. The components inside the engine such as turbine discs, compressor discs, blades, and casing, work under extreme conditions of high temperature, high pressure, and high rotational speed, and must use high-performance forgings to ensure their reliability and lifespan. The weight of forgings used in the engine structure accounts for approximately 30% to 45% of the engine's total weight.
Main forgings: including ring forgings (such as casing, installation edge, sealing ring, load-bearing ring, etc.), disc forgings (such as compressor disc, turbine disc), and blade forgings (such as fan blades, compressor moving blades, and stationary blades).
4. Special forgings for helicopters
In addition to the above general components, the forgings of helicopters are also concentrated in the rotor system and transmission system.
Main forgings: including engine turbine discs and turbine shafts, transmission box transmission clamps, super-large hub central parts, hub connection parts, hub shafts, and weapon hanger system forgings, etc.
With the development of aircraft manufacturing technology, aircraft forgings are evolving towards the direction of "large-scale, integrated, and precision". For example, changing the traditional multi-segment combined frames to a single frame can not only reduce the number of parts and connection components but also significantly improve the fatigue resistance and safety reliability of the aircraft.