Why can’t the aircraft be welded? Decades of doubt finally understood!
Welding is a process widely used in modern manufacturing industry. It has the advantages of fast speed and good sealing, and it shows its prominence in aerospace, shipbuilding and automobile manufacturing. So, can the aircraft also be welded during the manufacturing process? the answer is negative.
The main reasons are as follows:
First, it is caused by the manufacturing materials of the aircraft. Before the advent of Boeing 787 and Airbus A350XWB, the main manufacturing material of modern aircraft was aluminum alloy. This material has an outstanding feature-extremely poor welding performance. After welding using traditional welding methods, local stress concentration in the welding area makes the metal brittle, and it is easy to produce defects such as blisters, bubbles, and micro-cracks, which makes the performance of the structure at these locations lower than that of the non-welded area. This is unacceptable in aircraft manufacturing.
Although there are also some special welding processes, such as friction stir welding and laser welding, the related technology is too complicated and it is difficult to guarantee the stability of the process. For the same material, the thinner it is, the easier it is to weld. The thickness of the aircraft skin is generally only about 2 mm. Even if it can be welded, it will be very difficult. Non-general operators are competent, which is not conducive to mass production of aircraft.
Boeing 787 and Airbus A350XWB bodies are mainly made of composite materials. These composite materials are made of multiple single materials through composite methods and then made by special processes. The difficulty of welding is greater than that of aluminum alloys. Manufacturers rarely use welding. .