As we all know, the history of human civilization and progress is closely related to the development and progress of manufacturing technology. High-power lasers use "light energy" and "light tools" as new processing methods to be applied to material processing, playing an innovative pioneering role, representing the development direction of advanced manufacturing, and leading manufacturing technology into a new era of laser manufacturing, which has raised the technical level of traditional manufacturing, brought about a huge change in product design and manufacturing technology, and is triggering a revolution in manufacturing technology.
The application of modern laser technology in the aerospace field is mainly in cutting, marking, laser welding, laser quenching, laser cladding, laser drilling and other aspects.
The materials use aluminum alloy, stainless steel, titanium molybdenum, plastic and composite materials. In the manufacture of aerospace equipment, the shell is made of special metal materials with high strength, high hardness and high temperature resistance, which makes it difficult to complete the processing of materials by ordinary cutting methods. Laser cutting is an efficient processing for dealing with aircraft skin, honeycomb structure, frame, wing bin, tail avoiding plate, helicopter main rotor, engine casing and flame tube, etc. It generally uses a continuous output laser, but also a high-repetition carbon dioxide pulsed laser. The aspect ratio of laser cutting is high. For non-metals, the ratio can reach more than 100, and for metals it can reach about 20. The laser cutting speed is also high. It is 30 times that of the mechanical method to cut the titanium alloy sheet and 20 times that of the mechanical method to cut the steel plate. Such working efficiency can offer better cutting quality, and compared with oxyacetylene and plasma cutting methods, cutting carbon steel has the best quality.
In the aerospace industry, many parts are welded by electron beams. Since laser welding does not need to be carried out in a vacuum, laser welding is currently being used instead of electron beam welding. For a long time, the connection between aircraft structural parts has been using backward riveting technology. The main reason is that the aluminum alloy material used in the aircraft structure is heat-treated strengthened aluminum alloy (that is, high-strength aluminum alloy). Once welded, the heat treatment strengthening effect will be lost, and intergranular cracks are difficult to avoid. The use of laser welding technology overcomes such problems and greatly simplifies the manufacturing process of the aircraft fuselage, which reduces the weight of the fuselage by 18% and the cost by 21.4% to 24.3%. Laser welding technology is the best for aircraft of a technological revolution in manufacturing.
Laser engraving technology is suitable for drilling holes in instrument jewel bearings, air-cooled turbine blades, nozzles and combustion chambers in the aerospace industry. At present, in the processing of aero-engine parts, laser engraving is limited to processing the cooling holes of the stationary parts of the engine, because there are microscopic cracks on the surface of the holes. It is concluded through comprehensive analysis that laser engraving has the advantages of good effect, strong versatility, high efficiency and low cost.
